Solar Cell Physics: recombination and generation
|
|
- Sheryl Jacobs
- 5 years ago
- Views:
Transcription
1 NCN Summer School: July 2011 Solar Cell Physics: recombination and generation Prof. Mark Lundstrom Electrical and Computer Engineering Purdue University West Lafayette, Indiana USA
2 copyright 2011 This material is copyrighted by Mark Lundstrom under the following Creative Commons license. Conditions for using these materials is described at 2
3 acknowledgement Dionisis Berdebes, Jim Moore, and Xufeng Wang played key roles in putting together this tutorial. Their assistance is much appreciated. 3
4 solar cell physics A solar cell is a simple device just a pn junction with light shining on it. To maximize efficiency, we must maximize the generation of e-h pairs and minimize the recombination of e-h pairs. This lecture is a short introduction to the physics of crystalline solar cells specifically Si. 4
5 outline 1) Introduction 2) Recombination at short circuit 3) Recombination at open circuit 4) Discussion 5) Summary 5
6 dark current and recombination - N + P I D s.s. excess holes electron-injecting contact s.s. excess electrons hole-injecting contact V A + 6
7 recombination in the N-type QNR N - - P + I D electron-injecting contact hole-injecting contact V A + Anytime an electron and hole recombine anywhere within the diode, one electron flows in the external circuit. 7
8 Shockley-Read-Hall recombination minority carriers injected across junction Fn qv A FP E T SRH recombination I D V A + 8
9 recombination at a contact minority carriers injected across junction Fn qv A FP I D V A + 9
10 light-current and generation V bi V A E F base (absorbing layer) emitter V A + I D < 0 10 Every time a minority electron is generated and collected, one electron flows in the external current.
11 light-current and recombination 3 e-h pairs generated emitter 1 e in external circuit Every time a minority electron is generated and recombines before being collected, the solar cell current suffers. 11
12 solar cells and recombination Carrier recombination lowers the short-circuit current and reduces the open-circuit voltage. To optimize solar cell performance, we need a clear understanding of how many carriers are recombining and where they are recombining. Then we need to establish a quantitative relation between recombination and solar cell performance. 12
13 solar cells and recombination J p ( 0) N P Jn ( L) 0 L x I D ( ) ( ) ( ) J V = q R V G R D A TOT A TOT TOT L p = R x dx 0 L 0 ( ) ( ) GTOT = Gop x dx ( 0) ( ) J J L q n q For a formal derivation of this result, see the appendix. 13
14 outline 1) Introduction 2) Recombination at short circuit 3) Recombination at open circuit 4) Discussion 5) Summary 14
15 generic crystalline Si solar cell 200 um S F = 1000 cm/s n + emitter (0.3 μm) p-type base (198.9 μm) p + Back Surface Field (BSF) (0.8 μm) key device parameters base doping: N A = /cm 3 emitter doping N D = 6 x /cm 3 minority carrier lifetime τ n = 34 μs (base) base thickness W = μm front junction depth x jf = 0.3 μm back junction depth x jb = 0.8 μm 15
16 light-generated current 200 um S F = 1000 cm/s n + emitter (0.3 μm) p-type base (198.9 μm) p + Back Surface Field (BSF) (0.8 μm) 1) What is G TOT? 2) How is G TOT spatially distributed? 3) What is R TOT? ( ) ( 0) ( 0) J = q R G D TOT TOT 4) How is R TOT spatially distributed? 5) How do things change if we remove the BSF? 16
17 light-generated current: numbers 200 um p-type base (198.9 μm) n + emitter (0.3 μm) W 0.3 µ m D Ln 320 µ m p + Back Surface Field (BSF) (0.8 μm) ( 0) ( ) J = J V = = q R G SC D A TOT TOT G G x dx MAX 2L 0 ( ) G = G x dx = cm s TOT J SC q TOT 0 op op ( ) cm s = = ma/cm cm -2 s -1 = = q ( 0) cm s R = 17 CE = 0.88
18 light-generated current: understanding entire device near surface x j xj + WD 18
19 light-generated current: summary G G x dx MAX ( ) cm s = = 0 op 2L 0 ( ) G = G x dx = cm s TOT op low lifetime (Auger recombination) surface recombination 19 good collection minority carrier lifetime BSF
20 recombination at short circuit entire device near surface x + W x j j D 20
21 recombination at short circuit: summary J SC q ma/cm cm -2 s -1 q R 0 = cm s = = ( ) TOT (0.37) (0.14) (0.49) low lifetime (Auger recombination) surface recombination 21 good collection minority carrier lifetime BSF
22 about recombination in the base expect: R( x) ( ) n x τ n 2 d n n 0 2 dx = Ln= Dτ n n L n We find the excess minority electron profile by solving the minority carrier diffusion equation: n ( ) = ( ) J L qs n L n back d ( J n q ) = R dx d n J qd dx n n ( 0 ) = ( 0 ) J qs n n j = + W 0 xj L = L x BSF x xj + W L 22
23 Adept simulation results ( ) R x ( ) n x τ n n( x) 23
24 the BSF E = 0.13 ev E C E I E F S back υ th e E k BT ; cm s E V What happens if we remove the BSF? E C E I S back υ th E F ; cm s 24 E V
25 without the BSF BSF no BSF With BSF Without BSF J SC = ma/cm J SC = ma/cm 25 qr TOT = CE = ma/cm qr TOT = CE = ma/cm
26 internal quantum efficiency With BSF No BSF IQE = J D ( V = 0, λ ) F ( λ ) inc 26
27 questions 1) Can you determine a way to find the actual back surface recombination velocity from the Adept simulation results. (Hint: Use plots of n(x) and J n (x).) 2) How much could the performance improve if the back surface recombination velocity could be reduced to zero? 3) With the original BSF, how much would the performance increase if the minority carrier lifetime was 10 times longer? 4) In the original design, how would the short-circuit current change if the base was twice as thick? 27 5) Since most of the recombination loss occurs in the emitter, why not just make the emitter junction depth a lot smaller?
28 2D effects I D I( x) D V V ( x) < VD x j dx dr = ρs W ρ S ρ 1 = = x N qµ x j D n j distributed series resistance 28
29 outline 1) Introduction 2) Recombination at short circuit 3) Recombination at open circuit 4) Discussion 5) Summary 29
30 dark I-V ( ) ( ) ( ) J V = q R V G D A TOT A TOT ( ( ) ) 0 = q RTOT VA = VOC GTOT Under open circuit conditions: ( ) R V = V = G TOT A OC TOT 30
31 superposition ( ) ( ) ( ) J V = q R V G D A TOT A TOT J D dark IV dark: dark ( ) = ( ) J V qr V dark D A TOT A D J SC qvd nkbt ( ) J = J e 0 1 illuminated: V OC V A ( ) light ( ) ( ) J V = q R V G light D A TOT A TOT J SC J L < 0 illuminated at V OC : superposition: ( ) R V = G light TOT OC TOT? ( ) ( ) J V = J dark D OC SC R V = J q dark TOT OC SC 31
32 dark D dark current characteristics (sketch) qv ( ) 0 ( 1) A nkbt A = J V J e dark D qva kbt qva ( ) ( ) ( 2 kbt A = ) J V J e J e series resistance or log 10 dark J D shunt resistance or n = 2 n = 1 V A 32
33 dark D dark current characteristics (Adept) qv ( ) 0 ( 1) A nkbt A = J V J e dark D qva kbt qva ( ) ( ) ( 2 kbt A = ) J V J e J e n > 1 n = 1 n 2 33
34 what determines J 0 and n? dark D qv ( ) 0 ( 1) A nkbt A = J V J e Answer: dark ( ) = ( ) J V qr V dark A A TOT A Electron-hole recombination determines I 0. The location of recombination within the solar cell determines the ideality factor, n. 34
35 recombination in the dark (V A = 0.7 V) Emitter Base 35
36 recombination summary: (V A = 0.7 V) Short-circuit recombination V A = 0.7 V recombination light qr = TOT 2 ( 0) 5.3 ma/cm TOT 2 ( 0.7) 465 ma/cm dark qr = 36
37 what happens if we remove the BSF? (V A = 0.7 V) With BSF Without BSF ~70% ~85% 2 ( 0.7) 644 ma/cm J = D D 2 ( 0.7) 1372 ma/cm J = 37
38 dark current physics (n = 1) FB: minority carriers injected across junction ( ) = ( ) I V qr V D A TOT A 1) Recombination in QNRs: F n qv A F P I D > 0 2) Electrons and holes can also recombine within the SCR of the junction. 38
39 n = 1 device physics ( ) = ( ) I V qr V D A TOT A ( V ) qv bi A F n n P ( ) 0 n e qva B 0 P n n N 2 0P i A k T F P qr Q t n n TOT n ( V ) = n N 2 i A A Q t n ( qv 1) A kbt e : minority carier lifetime or base transit time Recombination in quasi-neutral regions gives rise to n = 1 currents. 39
40 dark D dark current characteristics (sketch) qv ( ) 0 ( 1) A nkbt A = J V J e dark D qva kbt qva ( ) ( ) ( 2 kbt A = ) J V J e J e series resistance or log 10 dark J D shunt resistance or n = 2 n = 1 V A 40
41 recombination in the dark (V A = 0.2 V) emitter region base region 41
42 recombination summary: (V A = 0.2 V) V A = 0.7 V recombination V A = 0.2 V recombination 2 ( 0.7) 465 ma/cm dark qr = TOT qr dark TOT 6 2 ( 0.7) = ma/cm 42
43 dark current physics FB: minority carriers injected across junction ( ) = ( ) I V qr V D A TOT A 1) Recombination in QNRs: F n qv A F P I D > 0 2) Electrons and holes can also recombine within the SCR of the junction. 43
44 recombination in SCRs ( V ) qv bi A Fn FP dark ( ) = ( ) J V qr V D A TOT A Maximum recombination occurs when n(x) p(x) 2 qva B ( ) ( ) = ne n x p x qva 2kBT ˆ ˆ i n p ne i k T np = n e qv k T 2 A B i qr dark TOT ( V ) A qn e i τ qv A eff 2k T B Recombination in space-charge regions gives rise to n = 2 currents. 44
45 recombination in SCR ( ) = ( ) J V qr V D A TOT A qva 2kBT ˆ ˆ i n p ne ( ) RV ˆ A nˆ = = τ eff ne i qv τ A eff /2k T B ( ) = ˆ J V qrw D A eff kt B q W eff = E ˆ E ˆ = V cm kt B q W eff = 11 nm Eˆ 45
46 dark IV D ( ) ( qv 2 ) ( 1 ) ( ) A kbt qva kbt qva nkbt A = = 0 1 J V J e J e J e Recombination in depletion regions J n e 02 i E G /2k T large bandgaps and low temperatures B Recombination in neutral regions J n e 01 2 i E G / k T small bandgaps and high temperatures B 46
47 questions 1) What do you expect to happen if the BSF were removed? Run an Adept simulation to confirm. 2) What do you expect to happen if the minority carrier lifetime were reduced to 0.1 microseconds? Run an Adept simulation. 3) Why is recombination in the emitter so important under shortcircuit conditions, but not under FB in the dark? 4) How much could V OC be increased if a BSF with near-zero surface recombination velocity could be achieved? 5) Series resistance affects the dark current, but it has no effect at open-circuit. What are the implications? 47
48 outline 1) Introduction 2) Recombination at short circuit 3) Recombination at open circuit 4) Discussion 5) Summary 48
49 reducing recombination higher material quality (longer lifetimes) ( ) ( ) ( ) J V = q R V G D A TOT A TOT thinner base layer (but optically thick) built-in fields back-surface-fields / minority carrier mirrors reducing contact areas. 49
50 high-efficiency Si solar cells 24.5% at 1 sun Martin Green Group UNSW Zhao, et al,
51 how good is superposition? V = 0.62 V - Dark V = 0.62 V - Illuminated OC 51
52 how good is superposition? (ii) dark J Ddark J dark D light D ( V 0) + J = superposition light J D 52
53 outline 1) Introduction 2) Recombination at short circuit 3) Recombination at open circuit 4) Discussion 5) Summary 53
54 summary 1) Diode current = q times (total recombination total generation) 2) At V OC, recombination = optical generation 3) At V = 0, recombination lowers the collection efficiency 4) Dark current tells us much about the internal recombination mechanisms 5) Solar cell design is all about maximizing total generation and minimizing total recombination. 6) Simulations can be useful for understanding especially if you look inside and not just at the IV. 54
55 questions 1) Introduction 2) Recombination at short circuit 3) Recombination at open circuit 4) Discussion 5) Summary 55
56 Appendices 1) Formal derivation of the relation between current and recombination/generation. 2) Mathematical justification of superposition 56
57 Appendix 1: current and recombination Formal derivation of the relation between current and recombination/generation. J p ( 0) N P Jn ( L) 0 L x I D R ( ) = ( ) J V q R G D TOT TOT TOT L p = R x dx 0 L 0 ( ) ( ) GTOT = Gop x dx ( 0) ( ) J J L q n q 57
58 continuity equation for electrons Wabash River Rate of increase of water level in lake = (in flow - outflow) + rain - evaporation n = ( J q) n t Lundstrom G R 58
59 solar cell physics semiconductor equations Conservation Laws: D =ρ = ( J ) ( ) n q Gop R = ( J ) ( ) p q Gop R (steady-state) 59 Relations: D= κε E = κε V 0 0 ( + ) D A ρ = q p n+ N N Jn = nqµ ne + qdn n J = pqµ E qd p p p p R= fnp (, ) G op etc. = optical generation rate
60 = diode current and recombination ( J ) n q ( Gop R) d ( J n q ) = G op R (1D) dx L L n = ( ) op ( ) 0 0 dj q R x G x dx I D N P 0 L x I D ( ) ( 0) = ( ) ( ) n n op 0 L J L J q R x G x dx 60
61 current and recombination-generation L ( ) ( 0) = ( ) ( ) + J ( 0) J ( 0) J L J q R x G x d x n n op p p 0 L { Jn ( 0) J p ( 0) } J D ( V ) q R( x) Gop ( x) dx Jn ( L) J p ( 0) + = = 0 ( ) = ( ) J V q R G D TOT TOT L ( ) ( ) ( 0) qr = q R x dx J L J TOT n p 0 L ( ) GTOT = Gop x dx 0 Lundstrom N P 0 L x I D 61
62 current and generation-recombination ( ) ( ) ( ) J V = q R V G D A TOT A TOT The diode current is q times the total recombination minus the total generation. The total recombination is the integrated recombination rate within the device plus the flux of minority carriers into each contact
63 Appendix 2: justifying superposition ( ) ( ) ( ) J V = q R V G (valid in light or dark) D A TOT A TOT dark ( ) ( ) J V = qr V (dark current) dark D A TOT A ( ) light ( 0) ( 0) J = q R G (short circuit current) light D TOT TOT dark light ( ) ( ) J V = J + J (principle of superposition) super D A D D 0 ( ) dark light ( ) ( ) ( ) J V qr V q R G super D A = TOT A + TOT 0 TOT (How does this compare to the exact answer?) 63
64 mathematical justification for superposition J D ( V A )= q R TOT V A ( ) G TOT ( ) (valid in light or dark) J D light light ( V A )= q R TOT ( V A ) G TOT ( ) J D super dark ( V A )= qr TOT light ( V A )+ q R TOT ( 0) G TOT ( ) (principle of superposition) light R TOT dark ( V A )= R TOT light ( V A )+ R TOT ( 0)?? (criterion to justify superposition) 64
Ideal Diode Equation II + Intro to Solar Cells
ECE-35: Spring 15 Ideal Diode Equation II + Intro to Solar Cells Professor Mark Lundstrom Electrical and Computer Engineering Purdue University, West Lafayette, IN USA lundstro@purdue.edu Pierret, Semiconductor
More information( )! N D ( x) ) and equilibrium
ECE 66: SOLUTIONS: ECE 66 Homework Week 8 Mark Lundstrom March 7, 13 1) The doping profile for an n- type silicon wafer ( N D = 1 15 cm - 3 ) with a heavily doped thin layer at the surface (surface concentration,
More informationMinority Carrier Diffusion Equation (MCDE)
ECE-305: Spring 2015 Minority Carrier Diffusion Equation (MCDE) Professor Mark undstrom Electrical and Computer Engineering Purdue University, West afayette, IN USA lundstro@purdue.edu Pierret, Semiconductor
More informationSolar cells operation
Solar cells operation photovoltaic effect light and dark V characteristics effect of intensity effect of temperature efficiency efficency losses reflection recombination carrier collection and quantum
More informationECE-305: Spring 2018 Exam 2 Review
ECE-305: Spring 018 Exam Review Pierret, Semiconductor Device Fundamentals (SDF) Chapter 3 (pp. 75-138) Chapter 5 (pp. 195-6) Professor Peter Bermel Electrical and Computer Engineering Purdue University,
More informationLecture 15 - The pn Junction Diode (I) I-V Characteristics. November 1, 2005
6.012 - Microelectronic Devices and Circuits - Fall 2005 Lecture 15-1 Lecture 15 - The pn Junction Diode (I) I-V Characteristics November 1, 2005 Contents: 1. pn junction under bias 2. I-V characteristics
More informationCarrier Recombination
Notes for ECE-606: Spring 013 Carrier Recombination Professor Mark Lundstrom Electrical and Computer Engineering Purdue University, West Lafayette, IN USA lundstro@purdue.edu /19/13 1 carrier recombination-generation
More informationSemiconductor Junctions
8 Semiconductor Junctions Almost all solar cells contain junctions between different materials of different doping. Since these junctions are crucial to the operation of the solar cell, we will discuss
More informationPHOTOVOLTAICS Fundamentals
PHOTOVOLTAICS Fundamentals PV FUNDAMENTALS Semiconductor basics pn junction Solar cell operation Design of silicon solar cell SEMICONDUCTOR BASICS Allowed energy bands Valence and conduction band Fermi
More informationHoles (10x larger). Diode currents proportional to minority carrier densities on each side of the depletion region: J n n p0 = n i 2
Part V. (40 pts.) A diode is composed of an abrupt PN junction with N D = 10 16 /cm 3 and N A =10 17 /cm 3. The diode is very long so you can assume the ends are at x =positive and negative infinity. 1.
More informationEE 5611 Introduction to Microelectronic Technologies Fall Tuesday, September 23, 2014 Lecture 07
EE 5611 Introduction to Microelectronic Technologies Fall 2014 Tuesday, September 23, 2014 Lecture 07 1 Introduction to Solar Cells Topics to be covered: Solar cells and sun light Review on semiconductor
More informationV BI. H. Föll: kiel.de/matwis/amat/semi_en/kap_2/backbone/r2_2_4.html. different electrochemical potentials (i.e.
Consider the the band diagram for a homojunction, formed when two bits of the same type of semicondutor (e.g. Si) are doped p and ntype and then brought into contact. Electrons in the two bits have different
More informationn N D n p = n i p N A
Summary of electron and hole concentration in semiconductors Intrinsic semiconductor: E G n kt i = pi = N e 2 0 Donor-doped semiconductor: n N D where N D is the concentration of donor impurity Acceptor-doped
More informationECE 606 Homework Week 7 Mark Lundstrom Purdue University (revised 2/25/13) e E i! E T
ECE 606 Homework Week 7 Mark Lundstrom Purdue University (revised 2/25/13) 1) Consider an n- type semiconductor for which the only states in the bandgap are donor levels (i.e. ( E T = E D ). Begin with
More informationElectronic Devices and Circuits Lecture 5 - p-n Junction Injection and Flow - Outline
6.012 - Electronic Devices and Circuits Lecture 5 - p-n Junction Injection and Flow - Outline Review Depletion approimation for an abrupt p-n junction Depletion charge storage and depletion capacitance
More informationECE-305: Spring Carrier Action: II. Pierret, Semiconductor Device Fundamentals (SDF) pp
ECE-305: Spring 015 Carrier Action: II Pierret, Semiconductor Device Fundamentals (SDF) pp. 89-104 Professor Mark Lundstrom Electrical and Computer Engineering Purdue University, West Lafayette, IN USA
More informationSemiconductor Physics fall 2012 problems
Semiconductor Physics fall 2012 problems 1. An n-type sample of silicon has a uniform density N D = 10 16 atoms cm -3 of arsenic, and a p-type silicon sample has N A = 10 15 atoms cm -3 of boron. For each
More informationComparison of Ge, InGaAs p-n junction solar cell
ournal of Physics: Conference Series PAPER OPEN ACCESS Comparison of Ge, InGaAs p-n junction solar cell To cite this article: M. Korun and T. S. Navruz 16. Phys.: Conf. Ser. 77 135 View the article online
More informationQuiz #1 Practice Problem Set
Name: Student Number: ELEC 3908 Physical Electronics Quiz #1 Practice Problem Set? Minutes January 22, 2016 - No aids except a non-programmable calculator - All questions must be answered - All questions
More informationSample Exam # 2 ECEN 3320 Fall 2013 Semiconductor Devices October 28, 2013 Due November 4, 2013
Sample Exam # 2 ECEN 3320 Fall 203 Semiconductor Devices October 28, 203 Due November 4, 203. Below is the capacitance-voltage curve measured from a Schottky contact made on GaAs at T 300 K. Figure : Capacitance
More informationSpring Semester 2012 Final Exam
Spring Semester 2012 Final Exam Note: Show your work, underline results, and always show units. Official exam time: 2.0 hours; an extension of at least 1.0 hour will be granted to anyone. Materials parameters
More informationFYS 3028/8028 Solar Energy and Energy Storage. Calculator with empty memory Language dictionaries
Faculty of Science and Technology Exam in: FYS 3028/8028 Solar Energy and Energy Storage Date: 11.05.2016 Time: 9-13 Place: Åsgårdvegen 9 Approved aids: Type of sheets (sqares/lines): Number of pages incl.
More informationElectrons are shared in covalent bonds between atoms of Si. A bound electron has the lowest energy state.
Photovoltaics Basic Steps the generation of light-generated carriers; the collection of the light-generated carriers to generate a current; the generation of a large voltage across the solar cell; and
More informationECE 305 Fall Final Exam (Exam 5) Wednesday, December 13, 2017
NAME: PUID: ECE 305 Fall 017 Final Exam (Exam 5) Wednesday, December 13, 017 This is a closed book exam. You may use a calculator and the formula sheet at the end of this exam. Following the ECE policy,
More informationLecture 16 The pn Junction Diode (III)
Lecture 16 The pn Junction iode (III) Outline I V Characteristics (Review) Small signal equivalent circuit model Carrier charge storage iffusion capacitance Reading Assignment: Howe and Sodini; Chapter
More information6.012 Electronic Devices and Circuits
Page 1 of 1 YOUR NAME Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology 6.12 Electronic Devices and Circuits Exam No. 1 Wednesday, October 7, 29 7:3 to 9:3
More informationThe Role of doping in the window layer on Performance of a InP Solar Cells USING AMPS-1D
IOSR Journal of Engineering (IOSRJEN) ISSN: 2250-3021 Volume 2, Issue 8(August 2012), PP 42-46 The Role of doping in the window layer on Performance of a InP Solar Cells USING AMPS-1D Dennai Benmoussa
More informationECE-305: Spring 2018 Final Exam Review
C-305: Spring 2018 Final xam Review Pierret, Semiconductor Device Fundamentals (SDF) Chapters 10 and 11 (pp. 371-385, 389-403) Professor Peter Bermel lectrical and Computer ngineering Purdue University,
More informationEECS130 Integrated Circuit Devices
EECS130 Integrated Circuit Devices Professor Ali Javey 9/18/2007 P Junctions Lecture 1 Reading: Chapter 5 Announcements For THIS WEEK OLY, Prof. Javey's office hours will be held on Tuesday, Sept 18 3:30-4:30
More informationThe Law of the Junction Revisited. Mark Lundstrom Network for Computational Nanotechnology and Purdue University ( ). (1)
The Law of the Junction Revisited Mark Lundstrom Network for Computational Nanotechnology and Purdue University Consider a one-sided, short base diode like that shown in Fig.. We usually analyze the I-V
More informationAppendix 1: List of symbols
Appendix 1: List of symbols Symbol Description MKS Units a Acceleration m/s 2 a 0 Bohr radius m A Area m 2 A* Richardson constant m/s A C Collector area m 2 A E Emitter area m 2 b Bimolecular recombination
More informationGetting J e (x), J h (x), E(x), and p'(x), knowing n'(x) Solving the diffusion equation for n'(x) (using p-type example)
6.012 - Electronic Devices and Circuits Lecture 4 - Non-uniform Injection (Flow) Problems - Outline Announcements Handouts - 1. Lecture Outline and Summary; 2. Thermoelectrics Review Thermoelectricity:
More informationLab #5 Current/Voltage Curves, Efficiency Measurements and Quantum Efficiency
Lab #5 Current/Voltage Curves, Efficiency Measurements and Quantum Efficiency R.J. Ellingson and M.J. Heben November 4, 2014 PHYS 4580, 6280, and 7280 Simple solar cell structure The Diode Equation Ideal
More informationThe Opto-Electronic Physics That Just Broke the Efficiency Record in Solar Cells
The Opto-Electronic Physics That Just Broke the Efficiency Record in Solar Cells Solar Energy Mini-Series Jen-Hsun Huang Engineering Center Stanford, California Sept. 26, 2011 Owen D. Miller & Eli Yablonovitch
More informationLecture 16 - The pn Junction Diode (II) Equivalent Circuit Model. April 8, 2003
6.012 - Microelectronic Devices and Circuits - Spring 2003 Lecture 16-1 Lecture 16 - The pn Junction Diode (II) Equivalent Circuit Model April 8, 2003 Contents: 1. I-V characteristics (cont.) 2. Small-signal
More informationPeak Electric Field. Junction breakdown occurs when the peak electric field in the PN junction reaches a critical value. For the N + P junction,
Peak Electric Field Junction breakdown occurs when the peak electric field in the P junction reaches a critical value. For the + P junction, qa E ( x) ( xp x), s W dep 2 s ( bi Vr ) 2 s potential barrier
More informationElectronic Supplementary Information. Recombination kinetics in silicon solar cell under low-concentration: Electroanalytical
Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics. This journal is the Owner Societies 2014 Electronic Supplementary Information Recombination kinetics in silicon solar cell
More informationET3034TUx Utilization of band gap energy
ET3034TUx - 3.3.1 - Utilization of band gap energy In the last two weeks we have discussed the working principle of a solar cell and the external parameters that define the performance of a solar cell.
More informationSemiconductor Physics fall 2012 problems
Semiconductor Physics fall 2012 problems 1. An n-type sample of silicon has a uniform density N D = 10 16 atoms cm -3 of arsenic, and a p-type silicon sample has N A = 10 15 atoms cm -3 of boron. For each
More informationRecombination: Depletion. Auger, and Tunnelling
Recombination: Depletion Region, Bulk, Radiative, Auger, and Tunnelling Ch 140 Lecture Notes #13 Prepared by David Gleason We assume: Review of Depletion Region Recombination Flat Quantum Fermi Levels
More informationFinal Examination EE 130 December 16, 1997 Time allotted: 180 minutes
Final Examination EE 130 December 16, 1997 Time allotted: 180 minutes Problem 1: Semiconductor Fundamentals [30 points] A uniformly doped silicon sample of length 100µm and cross-sectional area 100µm 2
More informationSemiconductor Physics Problems 2015
Semiconductor Physics Problems 2015 Page and figure numbers refer to Semiconductor Devices Physics and Technology, 3rd edition, by SM Sze and M-K Lee 1. The purest semiconductor crystals it is possible
More informationLecture 10 - Carrier Flow (cont.) February 28, 2007
6.720J/3.43J Integrated Microelectronic Devices - Spring 2007 Lecture 10-1 Lecture 10 - Carrier Flow (cont.) February 28, 2007 Contents: 1. Minority-carrier type situations Reading assignment: del Alamo,
More informationToward a 1D Device Model Part 1: Device Fundamentals
Toward a 1D Device Model Part 1: Device Fundamentals Lecture 7 9/29/2011 MIT Fundamentals of Photovoltaics 2.626/2.627 Fall 2011 Prof. Tonio Buonassisi 1 Learning Objectives: Toward a 1D Device Model 1.
More informationElectronic Supporting Information
Characterization of Planar Lead Halide Perovskite Solar Cells by Impedance Spectroscopy, Open Circuit Photovoltage Decay and Intensity-Modulated Photovoltage/Photocurrent Spectroscopy Adam Pockett 1, Giles
More information6.012 Electronic Devices and Circuits
Page 1 of 12 YOUR NAME Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology 6.012 Electronic Devices and Circuits FINAL EXAMINATION Open book. Notes: 1. Unless
More informationFundamentals of Photovoltaics: C1 Problems. R.Treharne, K. Durose, J. Major, T. Veal, V.
Fundamentals of Photovoltaics: C1 Problems R.Treharne, K. Durose, J. Major, T. Veal, V. Dhanak @cdtpv November 3, 2015 These problems will be highly relevant to the exam that you will sit very shortly.
More informationThermionic Current Modeling and Equivalent Circuit of a III-V MQW P-I-N Photovoltaic Heterostructure
Thermionic Current Modeling and Equivalent Circuit of a III-V MQW P-I-N Photovoltaic Heterostructure ARGYRIOS C. VARONIDES Physics and Electrical Engineering Department University of Scranton 800 Linden
More informationIntroductory Nanotechnology ~ Basic Condensed Matter Physics ~
Introductory Nanotechnology ~ Basic Condensed Matter Physics ~ Atsufumi Hirohata Department of Electronics Quick Review over the Last Lecture Classic model : Dulong-Petit empirical law c V, mol 3R 0 E
More informationρ ρ LED access resistances d A W d s n s p p p W the output window size p-layer d p series access resistance d n n-layer series access resistance
LED access resistances W the output window size p-layer series access resistance d p n-layer series access resistance d n The n-layer series access resistance R = ρ s n where the resistivity of the n-layer
More informationLecture 20 - p-n Junction (cont.) October 21, Non-ideal and second-order effects
6.70J/3.43J - Integrated Microelectronic Devices - Fall 00 Lecture 0-1 Lecture 0 - p-n Junction (cont.) October 1, 00 Contents: 1. Non-ideal and second-order effects Reading assignment: del Alamo, Ch.
More informationToward a 1D Device Model Part 2: Material Fundamentals
Toward a 1D Device Model Part 2: Material Fundamentals Lecture 8 10/4/2011 MIT Fundamentals of Photovoltaics 2.626/2.627 Fall 2011 Prof. Tonio Buonassisi 1 2.626/2.627 Roadmap You Are Here 2 2.626/2.627:
More informationLecture 15 The pn Junction Diode (II)
Lecture 15 The pn Junction Diode (II I-V characteristics Forward Bias Reverse Bias Outline Reading Assignment: Howe and Sodini; Chapter 6, Sections 6.4-6.5 6.012 Spring 2007 Lecture 15 1 1. I-V Characteristics
More informationThe 5 basic equations of semiconductor device physics: We will in general be faced with finding 5 quantities:
6.012 - Electronic Devices and Circuits Solving the 5 basic equations - 2/12/08 Version The 5 basic equations of semiconductor device physics: We will in general be faced with finding 5 quantities: n(x,t),
More informationChapter 7. Solar Cell
Chapter 7 Solar Cell 7.0 Introduction Solar cells are useful for both space and terrestrial application. Solar cells furnish the long duration power supply for satellites. It converts sunlight directly
More informationECE 340 Lecture 21 : P-N Junction II Class Outline:
ECE 340 Lecture 21 : P-N Junction II Class Outline: Contact Potential Equilibrium Fermi Levels Things you should know when you leave Key Questions What is the contact potential? Where does the transition
More information3.1 Introduction to Semiconductors. Y. Baghzouz ECE Department UNLV
3.1 Introduction to Semiconductors Y. Baghzouz ECE Department UNLV Introduction In this lecture, we will cover the basic aspects of semiconductor materials, and the physical mechanisms which are at the
More informationRecitation 17: BJT-Basic Operation in FAR
Recitation 17: BJT-Basic Operation in FAR BJT stands for Bipolar Junction Transistor 1. Can be thought of as two p-n junctions back to back, you can have pnp or npn. In analogy to MOSFET small current
More informationSemiconductor device structures are traditionally divided into homojunction devices
0. Introduction: Semiconductor device structures are traditionally divided into homojunction devices (devices consisting of only one type of semiconductor material) and heterojunction devices (consisting
More informationThis is the 15th lecture of this course in which we begin a new topic, Excess Carriers. This topic will be covered in two lectures.
Solid State Devices Dr. S. Karmalkar Department of Electronics and Communication Engineering Indian Institute of Technology, Madras Lecture - 15 Excess Carriers This is the 15th lecture of this course
More information1 Name: Student number: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND. Fall :00-11:00
1 Name: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND Final Exam Physics 3000 December 11, 2012 Fall 2012 9:00-11:00 INSTRUCTIONS: 1. Answer all seven (7) questions.
More informationLecture 4 - PN Junction and MOS Electrostatics (I) Semiconductor Electrostatics in Thermal Equilibrium September 20, 2005
6.012 - Microelectronic Devices and Circuits - Fall 2005 Lecture 4-1 Contents: Lecture 4 - PN Junction and MOS Electrostatics (I) Semiconductor Electrostatics in Thermal Equilibrium September 20, 2005
More informationLecture 7 PN Junction and MOS Electrostatics(IV) Metal Oxide Semiconductor Structure (contd.)
Lecture 7 PN Junction and MOS Electrostatics(IV) Metal Oxide Semiconductor Structure (contd.) Outline 1. Overview of MOS electrostatics under bias 2. Depletion regime 3. Flatband 4. Accumulation regime
More informationDepartment of Electrical and Computer Engineering, Cornell University. ECE 3150: Microelectronics. Spring Due on March 01, 2018 at 7:00 PM
Department of Electrical and Computer Engineering, Cornell University ECE 3150: Microelectronics Spring 2018 Homework 4 Due on March 01, 2018 at 7:00 PM Suggested Readings: a) Lecture notes Important Note:
More informationELEC 3908, Physical Electronics, Lecture 19. BJT Base Resistance and Small Signal Modelling
ELEC 3908, Physical Electronics, Lecture 19 BJT Base Resistance and Small Signal Modelling Lecture Outline Lecture 17 derived static (dc) injection model to predict dc currents from terminal voltages This
More informationUNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences. Professor Chenming Hu.
UNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences EECS 130 Spring 2009 Professor Chenming Hu Midterm I Name: Closed book. One sheet of notes is
More informationSimulation of Quantum Dot p-i-n Junction Solar Cell using Modified Drift Diffusion Model
International Journal of Pure and Applied Physics. ISSN 0973-1776 Volume 13, Number 1 (017), pp. 59-66 Research India Publications http://www.ripublication.com Simulation of Quantum Dot p-i-n Junction
More informationFebruary 1, 2011 The University of Toledo, Department of Physics and Astronomy SSARE, PVIC
FUNDAMENTAL PROPERTIES OF SOLAR CELLS February 1, 2011 The University of Toledo, Department of Physics and Astronomy SSARE, PVIC Principles and Varieties of Solar Energy (PHYS 4400) and Fundamentals of
More informationcollisions of electrons. In semiconductor, in certain temperature ranges the conductivity increases rapidly by increasing temperature
1.9. Temperature Dependence of Semiconductor Conductivity Such dependence is one most important in semiconductor. In metals, Conductivity decreases by increasing temperature due to greater frequency of
More informationSession 5: Solid State Physics. Charge Mobility Drift Diffusion Recombination-Generation
Session 5: Solid State Physics Charge Mobility Drift Diffusion Recombination-Generation 1 Outline A B C D E F G H I J 2 Mobile Charge Carriers in Semiconductors Three primary types of carrier action occur
More informationEE 6313 Homework Assignments
EE 6313 Homework Assignments 1. Homework I: Chapter 1: 1.2, 1.5, 1.7, 1.10, 1.12 [Lattice constant only] (Due Sept. 1, 2009). 2. Homework II: Chapter 1, 2: 1.17, 2.1 (a, c) (k = π/a at zone edge), 2.3
More informationEE105 - Fall 2006 Microelectronic Devices and Circuits
EE105 - Fall 2006 Microelectronic Devices and Circuits Prof. Jan M. Rabaey (jan@eecs) Lecture 21: Bipolar Junction Transistor Administrative Midterm Th 6:30-8pm in Sibley Auditorium Covering everything
More informationECE 305 Exam 3: Spring 2015 March 6, 2015 Mark Lundstrom Purdue University
NAME: PUID: : ECE 305 Exam 3: March 6, 2015 Mark Lundstrom Purdue University This is a closed book exam You may use a calculator and the formula sheet at the end of this exam Following the ECE policy,
More informationSOLUTIONS: ECE 606 Homework Week 10 Mark Lundstrom. Purdue University. (Revised 3/29/13)
ECE- 66 SOLUTIOS: ECE 66 Homework Week 1 Mark Lundstrom (Revised 3/9/13) 1) In a forward- biased P junction under low- injection conditions, the QFL s are aroximately flat from the majority carrier region
More informationECE-305: Fall 2016 Minority Carrier Diffusion Equation (MCDE)
ECE-305: Fall 2016 Minority Carrier Diffusion Equation (MCDE) Professor Peter Bermel Electrical and Computer Engineering Purdue University, West Lafayette, IN USA pbermel@purdue.edu Pierret, Semiconductor
More informationSilicon Concentrator Solar Cells: Fabrication, Characterization and Development of Innovative Designs.
University of Trento Department of Physics Doctoral School in Physics, XXV cycle Phd Thesis Silicon Concentrator Solar Cells: Fabrication, Characterization and Development of Innovative Designs. Candidate:
More informationFor the following statements, mark ( ) for true statement and (X) for wrong statement and correct it.
Benha University Faculty of Engineering Shoubra Electrical Engineering Department First Year communications. Answer all the following questions Illustrate your answers with sketches when necessary. The
More informationLecture 13 - Carrier Flow (cont.), Metal-Semiconductor Junction. October 2, 2002
6.72J/3.43J - Integrated Microelectronic Devices - Fall 22 Lecture 13-1 Contents: Lecture 13 - Carrier Flow (cont.), Metal-Semiconductor Junction October 2, 22 1. Transport in space-charge and high-resistivity
More informationChalcogenide semiconductor research and applications. Tutorial 2: Thin film characterization. Rafael Jaramillo Massachusetts Institute of Technology
Chalcogenide semiconductor research and applications Tutorial 2: Thin film characterization Rafael Jaramillo Massachusetts Institute of Technology Section 1: Measuring composition August 20, 2017 Jaramillo
More informationUniform excitation: applied field and optical generation. Non-uniform doping/excitation: diffusion, continuity
6.012 - Electronic Devices and Circuits Lecture 2 - Uniform Excitation; Non-uniform conditions Announcements Review Carrier concentrations in TE given the doping level What happens above and below room
More informationLecture 6 PN Junction and MOS Electrostatics(III) Metal-Oxide-Semiconductor Structure
Lecture 6 PN Junction and MOS Electrostatics(III) Metal-Oxide-Semiconductor Structure Outline 1. Introduction to MOS structure 2. Electrostatics of MOS in thermal equilibrium 3. Electrostatics of MOS with
More informationLecture 27: Introduction to Bipolar Transistors
NCN www.nanohub.org ECE606: Solid State Devices Lecture 27: Introduction to ipolar Transistors Muhammad Ashraful Alam alam@purdue.edu Alam ECE 606 S09 1 ackground E C E C ase! Point contact Germanium transistor
More informationModeling Recombination in Solar Cells
Macalester Journal of Physics and Astronomy Volume 6 Issue 1 Spring 2018 Article 2 Modeling Recombination in Solar Cells Paul Chery Macalester College, pchery@macalester.edu Abstract Solar cells are a
More informationChapter 7. The pn Junction
Chapter 7 The pn Junction Chapter 7 PN Junction PN junction can be fabricated by implanting or diffusing donors into a P-type substrate such that a layer of semiconductor is converted into N type. Converting
More informationSemiconductor Device Physics
1 Semiconductor Device Physics Lecture 3 http://zitompul.wordpress.com 2 0 1 3 Semiconductor Device Physics 2 Three primary types of carrier action occur inside a semiconductor: Drift: charged particle
More informationCLASS 3&4. BJT currents, parameters and circuit configurations
CLASS 3&4 BJT currents, parameters and circuit configurations I E =I Ep +I En I C =I Cp +I Cn I B =I BB +I En -I Cn I BB =I Ep -I Cp I E = I B + I C I En = current produced by the electrons injected from
More informationEE 130 Intro to MS Junctions Week 6 Notes. What is the work function? Energy to excite electron from Fermi level to the vacuum level
EE 13 Intro to S Junctions eek 6 Notes Problem 1 hat is the work function? Energy to ecite electron from Fermi level to the vacuum level Electron affinity of 4.5eV Electron affinity of Ge 4.eV orkfunction
More informationFYS3410 Condensed matter physics
FYS3410 Condensed matter physics Lecture 23 and 24: pn-junctions and electrooptics Randi Haakenaasen UniK/UiO Forsvarets forskningsinstitutt 11.05.2016 and 18.05.2016 Outline Why pn-junctions are important
More informationOPTI510R: Photonics. Khanh Kieu College of Optical Sciences, University of Arizona Meinel building R.626
OPTI510R: Photonics Khanh Kieu College of Optical Sciences, University of Arizona kkieu@optics.arizona.edu Meinel building R.626 Announcements Homework #6 is assigned, due May 1 st Final exam May 8, 10:30-12:30pm
More informationAvailable online at Energy Procedia 00 (2009) Energy Procedia 2 (2010) E-MRS Spring meeting 2009, Symposium B
Available online at www.sciencedirect.com Energy Procedia 00 (2009) 000 000 Energy Procedia 2 (2010) 169 176 Energy Procedia www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia E-MRS Spring
More informationEE105 Fall 2015 Microelectronic Devices and Circuits: Semiconductor Fabrication and PN Junctions
EE105 Fall 2015 Microelectronic Devices and Circuits: Semiconductor Fabrication and PN Junctions Prof. Ming C. Wu wu@eecs.berkeley.edu 511 Sutardja Dai Hall (SDH) 1 pn Junction p-type semiconductor in
More informationLecture 19 - p-n Junction (cont.) October 18, Ideal p-n junction out of equilibrium (cont.) 2. pn junction diode: parasitics, dynamics
6.720J/3.43J - Integrated Microelectronic Devices - Fall 2002 Lecture 19-1 Lecture 19 - p-n Junction (cont.) October 18, 2002 Contents: 1. Ideal p-n junction out of equilibrium (cont.) 2. pn junction diode:
More informationChapter 6 Solar Cells (Supplementary)
1 Chapter 6 olar Cells (upplementary) Chapter 6... 1 olar Cells... 1 6.1.1... 6.1.... 6.1.3... 6.1.4 Effect of Minority Electron Lifetime on Efficiency... 6.1.5 Effect of Minority hole Lifetime on Efficiency...
More informationLecture 17 - p-n Junction. October 11, Ideal p-n junction in equilibrium 2. Ideal p-n junction out of equilibrium
6.72J/3.43J - Integrated Microelectronic Devices - Fall 22 Lecture 17-1 Lecture 17 - p-n Junction October 11, 22 Contents: 1. Ideal p-n junction in equilibrium 2. Ideal p-n junction out of equilibrium
More informationpn JUNCTION THE SHOCKLEY MODEL
The pn Junction: The Shockley Model ( S. O. Kasap, 1990-001) 1 pn JUNCTION THE SHOCKLEY MODEL Safa Kasap Department of Electrical Engineering University of Saskatchewan Canada Although the hole and its
More informationLecture-4 Junction Diode Characteristics
1 Lecture-4 Junction Diode Characteristics Part-II Q: Aluminum is alloyed into n-type Si sample (N D = 10 16 cm 3 ) forming an abrupt junction of circular cross-section, with an diameter of 0.02 in. Assume
More informationESE 372 / Spring 2013 / Lecture 5 Metal Oxide Semiconductor Field Effect Transistor
Metal Oxide Semiconductor Field Effect Transistor V G V G 1 Metal Oxide Semiconductor Field Effect Transistor We will need to understand how this current flows through Si What is electric current? 2 Back
More informationThermionic emission vs. drift-diffusion vs. p-n junction
6.772/SMA5111 - Compound Semiconductors Lecture 4 - Carrier flow in heterojunctions - Outline A look at current models for m-s junctions (old business) Thermionic emission vs. drift-diffusion vs. p-n junction
More informationSolid State Electronics. Final Examination
The University of Toledo EECS:4400/5400/7400 Solid State Electronic Section elssf08fs.fm - 1 Solid State Electronics Final Examination Problems Points 1. 1. 14 3. 14 Total 40 Was the exam fair? yes no
More informationSolid State Physics SEMICONDUCTORS - IV. Lecture 25. A.H. Harker. Physics and Astronomy UCL
Solid State Physics SEMICONDUCTORS - IV Lecture 25 A.H. Harker Physics and Astronomy UCL 9.9 Carrier diffusion and recombination Suppose we have a p-type semiconductor, i.e. n h >> n e. (1) Create a local
More information