Carbon Nanotubes for Photovoltaic Applications. Fernando Langa. Univ. of Castilla-La Mancha Toledo, Spain

Transcription

1 Carbon anotubes for Photovoltaic Applications Fernando Langa Univ. of Castilla-La Mancha Toledo, pain MICI-JT Joint Workshop, Barcelona, March 10 th -12 th, 2010

2 Madrid Toledo

3 Outline: 1. Photoinduced Electron Transfer in ystems Based on Fullerenes 2. Organic Dyes for Graetzel olar Cells. 3. Functionalization of Carbon anoforms. 4. Carbon anotubes for Photovoltaic Applications.

4 Aviram-Ratner Concept Acceptor Donor e - Ari Aviram Aviram, A., Ratner, M.A., Chem. Phys. Lett., 29, (1974).

5 Molecular electronics Molecular electronics can be defined as technology utilizing single molecules, small groups of molecules, carbon nanotubes or nanoscale metallic or semiconductor wires to perform electronic functions. Any device utilizing molecular properties is a molecular electronic device. Wires witches Transistors Molecular electronics Data storage OLEDs Photovoltaic devices

6 hν D * B A D + - B A ELECTRO DOOR (D) BRIDGE ACCEPTOR (A) YTEM

7 Pyrazolinofullerene derivatives These systems show better electron affinity than other fullerene derivatives and similar E 1 red to that of C 60 H 3 C O 2 E 1 red = V E 1 red = V J. Org. Chem. 2004, 69, 2661 Ar Ar CuTf 2 o-dcb, Reflux Org. Lett. 2008, 10, 3705 J. Org. Chem. 2008, 73, 3184 CH, 48 h. 1% MW, 12 h. 5%

8 organic solar cells CF 3 F 3 C O 2 O CH 3 η = 0.3 % O n F 3 C PCBM η = 0.17 % - + APFO GREE 1 F 3 C O 2 e - Al A D ITO glass light - + Appl. Phys. Lett. 2004, 85, Adv. Funct. Mater. 2005, 15, Organic Electronics 2006, 7, 195. η = 0.7 %

9 Fe Fe Fe CH 3 Fe Chem. A Eur. J. 2006, 12, 5149 J. Mat. Chem, 2002, 12, 2077 Chem. Eur. J. 2005, 11, 4405

10 Liquid crystaline sensor for acids Donor Acceptor Mesogenic unit Chem. Commun., 2008,

11 Liquid crystaline sensor for acids Bu 2 h 380 nm h 380 nm ET HBu 2 E O Mesogen(Gn) O Mesogen(Gn) Bu 2 Bu 2 H TFA Et nm (weak) no emission 485 nm (strong) 708 nm Chem. Commun., 2008,

12 Porphyrins and fullerenes π-conjugated wire Donor Acceptor k ET ( ) ( R ee ) R k e β = 0 The rate of ET depends on the distance and the attenuation factor (β)

13 Attenuation factor (β) for π-conjugated wires β = 0.08 Å -1 J. Am. Chem. oc. 1997, 119, β = 0.10 Å -1 Angew. Chem. Int. Ed. Engl. 1995, 34, 1100 n β = 0.4 Å -1 J. Am. Chem. oc. 1992, 114, 6227 n β = 0.03 Å -1 J. Phys. Chem. A, 2006, 110, 319 β = 0.11 Å -1 aturated bridges β = Å -1 J. Phys. Chem. B, 2004, 108, J. Am. Chem. oc. 1989, 93, 3258

14 OPVs as wires β = 0.04 Å -1 Wasielewski et al., ature, 1998, 396, 60 RO H 3 C OR n=1;3 β = 0.03 Å -1 Martín; Guldi et al., Chem. Eur. J., 2005, 11, 1267 β = 0.01 Å -1 Martín, Guldi et al., Chem. Eur. J., 2005, 11, 4819

15 Fc-nTV-C 60 triads Fe H 13 C 6 C 6 H 13 H 13 C 6 C 6 H 13 Lifetime of charge separated state: <6 ns k cs = 2,3 x 10 9 s -1 Φ = 0.63 HOMO C 60-2TV-Fc LUMO C 60-2TV-Fc Fe H 13 C 6 C 6 H 13 H 13 C 6 C 6 H 13 H 13 C 6 C 6 H 13 H 13 C 6 C 6 H 13 Lifetime of charge separated state: 12 ns k cs = 9,3 x 10 9 s -1 Φ = 0.93 Chemistry. A Eur. J. 2007, 13, 3924

16 ZnPorphyrin-nTV-C 60 triads CH 3 CH 3 C 6 H 13 C 6 H 13 H 3 C C 6 H 13 C 6 H 13 Zn CH 3 CH 3 H 3 C CH 3 H 3 C CH 3 ZnPor-2TV-C 60 H 3 C Chem. Commun. 2007, 4425

17 Zn-Porphyrin-nTV-C 60 triads H 3 C CH 3 H 3 C CH 3 H 3 C CH 3 C 6 H 13 C 6 H 13 Zn CH 3 CH 3 H 3 C C 6 H 13 C 6 H 13 C 6 H 13 C 6 H 13 CH 3 ZnPor-3TV-C 60

18 Zn-Porphyrin-nTV-C 60 triads CH 3 C 6 H 13 C 6 H 13 C 6 H 13 C 6 H 13 H 3 C C 6 H 13 C 6 H 13 C 6 H 13 C 6 H 13 Zn CH 3 CH 3 CH 3 H 3 C CH 3 H 3 C CH 3 ZnPor-4TV-C 60 H 3 C

19 Zn-Porphyrin-nTV-C 60 triads ZnPor-8TV-C 60 Distance Porphyrin-C 60 : 57.8 Å

20 Principal features of C process solvent k C Φ C k CR /s -1 τ RIP /μs ZnP-2TV-C 60 Toluene ( ) (0.97) PhC ZnP-4TV-C 60 Toluene PhC ZnP-8TV-C 60 Toluene PhC Lifetime of Charge separated state is in the order of μs!!

21 Minimal value for the attenuation factor 24.0 olvent: benzonitrile PhC ln(k C(P* - C) ) k ET R = k 0 e ( ) ( βr ee ) β = Å x x x x x x x x10-9 R CC(P - C) / m Plot of ln(k C(P*-C) ) vs R CC(P-C) in PhC for ZnP-nTV-C 60.

22 Comparison of β values between OPV and OTV Ar CH 3 OC 6 H 13 n OC 6 H 13 n=1,2 n Zn Ar Ar β = 0.03 Å -1 Martín; Guldi et al., Chem. Eur. J., 2005, 11, 1267 Ar CH 3 C 6 H 13 C 6 H 13 Zn Ar β = Å -1 C 6 H 13 C 6 H 13 n= 1, 2, 4 n Ar Chem. Commun. 2007, 4425

23 1. Photoinduced Electron Transfer in ystems Based on Fullerenes. 2. Organic Dyes for Graetzel olar Cells. 3. Functionalization of Carbon anoforms. 4. Carbon anotubes for Photovoltaic Applications.

24 DC (GRÄTZEL CELL) e V e - e - e - TiO 2 b.c e - LUMO Dye* V oc e - 0.5V 0.7V e -- I 3- / I- Dye HOMO I 3 - I - e - e - Glass-FTO Glass-FTO/Pt e - hυ e -

25 Ru Dyes HOOC COOTBA C HOOC Ru C 719 Metal Free Dyes COOTBA

26 The perfect sensitizer Absorbs all the sunlight below 900 nm. Is endowed with groups (carboxylate or phosphonate) that anchor it firmly to the TiO 2 surface. hows a high quantum yield of electron injection. table under long term illumination and Tª. o aggregation phenomena. HOMO has to be more positive than the redox potential of iodine/iodide. LUMO has to be sufficiently more negative than the conduction band edge of the TiO 2

27 FL-4 Absorbance (a.u) FL Wavelength(nm) J. Phys. Chem. C, 2008, 112, 18623

28 15 J sc (ma/cm 2 ) %MBI 50%MBI 0%MBI Refer 719 IPCE= 58% J sc = 13.4 ma/cm 2 V oc =0.5 V FF= 0.57 η(%) = Voltage (V) J. Phys. Chem. C, 2008, 112, 18623

29 R R R R C n COOH R = Hexyl n = LUMO n2tvacido n3tvacido n4tvacido n6tvacido Energy -6-8 HOMO HOMO-1 Absorption ntv wavelength (nm) ChemPhysChem 2010, 11, 245

30 R R R R C n COOH R = Hexyl 2tv 3tv 4tv 5tv 6tv n = 1-5 Dye Eficiency (%) 12 2TV 1.43 J(mA/cm 2 ) TV TV TV TV 1.80 V/V ChemPhysChem 2010, 11, 245, mall, 2010, 6, 221

31 ew Dyes FL-7 0,6 0,5 0,4 0,3 0,2 0,1 0, dye J sc [macm -2 ] V oc FF η[%] FL FL ChemusChem 2009, 2, 344

32 1. Photoinduced Electron Transfer in ystems Based on Fullerenes 2. Organic Dyes for Graetzel olar Cells. 3. Functionalization of Carbon anoforms. 4. Carbon anotubes for Photovoltaic Applications.

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34 Excellent Properties Low solubility Lack of response Applications limited WT Response to external stimuli -Chemical -Electrochemical -Photochemical - -oluble -Activity Chemical functionalization Applications improved

35 Purification of CTs by Oxidation Carbon HO 3 Reflux Catalist horter WT

36 Functionalization of WT

37 HOOC HOOC HOOC HOOC COOH COOH COOH COOH (a) (a) Air atmosphere (b) Under 2 (c) Without ilumination 1) Cl 2 O, reflux, 24 h 2) n-c 5 H 11 OH, 80º, 72 h Intensity (na) (b) (c) OOC OOC OOC OOC COO COO COO COO Wavelength (nm) 0,3 0,2 0,1 0, Time (s) E-WT solution in CHCl 3 Chem. Phys. Letters, 2004, 386

38 A novel hybrid carbon material The field-emission characteristics of anobuds suggest that they may possess advantageous properties compared with singlewalled nanotubes or fullerenes alone. Kauppinen et al.ature anotechnology, 2007, 2, 156

39 The first conjugated WT-C 60 hybrid HR-TEM Carbon, 2007, 45, 2250

40 OOC OOC OOC O 2 n COO COO COO OOC COO Chem. Commun, 2004, 1734 J. Phys. Chem B., 2004, 108, J. Am. Chem. oc. 2006, 128, 6626 J. Mat. Chem. 2008, 18, 1592

41 CH-BAED PHOTOVOLTAIC CELL O C H H 3 + Cl - + Zn O O O O O O O O CH-sp-H 3 + Crown Zn-P O C H O O O H O H H O O O O Zn CH-sp-H 3 + ;CrownZn-P (submitted )

42 CH-BAED PHOTOVOLTAIC CELL supramolecular complex formation? 14 Absorbance / a.u. 0,20 0,15 0,10 0,05 Absorbance / a.u. 0,24 0,20 0,16 0,12 0,08 0,04 0, wavelenght / nm [ZnP crown ether] = 10-7 M [H ox -H 3 + Cl - ] = 0.5 mg / 100 ml DMF Intensity / a.u [ZnP crown ether] = 10-7 M [H ox -H 3 + Cl - ] = 0.5 mg / 100 ml DMF, λ exc : 560 nm quenching: 55% wavelength / nm 0, λ / nm 0,0 0,2 0,4 0,6 0,8 1,0 Potential (V) vs Ag/AgO 3

43 CH-BAED PHOTOVOLTAIC CELL e - hυ e - no 2 hυ e - e - e - e - hυ I 3 - e - e - e - e - I - e - OTE IPCE of 9% Pt e - e - e -

44 Photocurrent action spectra of IPCE (a) OTE/nO 2 /CH-sp-H 3+ ;Crown-ZnP (b) OTE/nO 2 /CH-sp-H 3 + (c) OTE/nO 2 /Crown-ZnP Photocurrent generation responses of (a)ote/no 2 /CH-sp-H 3+ ;Crown-ZnP (b) OTE/nO 2 /CH-sp-H 3 +

45 Final Remarks everal examples of Fullerene-based donor acceptor systems are presented. ew Dyes for DC have been prepared and studied. Properties of Carbon anotubes can be tailored by chemical functionalization. A photovoltaic cell based on Carbon Horns is presented.

46 Thanks!! Collaborations CH: Prof.. Iijima Dr. M. Yudasaka Photophysics: Prof. O. Ito DC: Prof. J. Bisquert Prof. E. Palomares Organic cells Prof. Inganas