Thermophotovoltaic devices for solar and thermal energy conversion

Transcription

1 Journées Nationales sur l'énergie Solaire «Congrès JNES 2018» June 2018 Campus de LyonTech-la Doua, Villeurbanne, France Thermophotovoltaic devices for solar and thermal energy conversion Rodolphe Vaillon, Christophe Lucchesi, Etienne Blandre, P-Olivier Chapuis 1 Centre for Energy and Thermal Sciences of Lyon, Univ Lyon, CNRS, INSA-Lyon, Université Lyon 1, Villeurbanne, France Dilek Cakiroglu, Jean-Philippe Pérez, Thierry Taliercio, Eric Tournié 2 Institut d Electronique et des Systèmes, Université de Montpellier, CNRS, Montpellier, France Elisa Antolin, Alejandro Datas, Antonio Marti 3 Insituto de Energia Solar, Universidad Politecnica de Madrid, Madrid, Spain Daniel Milovich, John DeSutter, Lei Tang, Mathieu Francoeur 4 Radiative Energy Transfer Laboratory, Department of Mechanical Engineering, University of Utah, Salt Lake City, USA Makoto Shimizu, Asaka Kohiyama, Hiroo Yugami 5 Graduate School of Engineering, Tohoku University, Sendai, Japan

2 Outline Thermophotovoltaics (TPV) Solar thermophotovoltaic devices Concept: using an intermediate solar absorber thermal emitter Key challenges Ongoing research and sample results Thermionic-thermophotovoltaic devices Concept: high-temperature energy storage and hybrid conversion Key challenges Ongoing research and sample results Near-field thermophotovoltaic devices Concept: electrical power enhancement using evanescent waves Key challenges Ongoing research and sample results Conclusions R. Vaillon et al. JNES 2018, 06/28/2018 2

3 Solar/Thermo-photovoltaics Solar photovoltaics SUN 5800 K Irradiation spectrum [ ] microns not tunable W= sr concentration PV cell C = (max) cooling system q Sun (AM1.5)=1 kw m -2 PV cell materials Si, CIGS, CdTe, AsGa,, perovskites bandgap E g ~ [1-1.5] ev Best (research) conversion efficiencies % (SJ) > 45% (MJ) NREL chart, 2018 Max: 33% (no conc.), 41% (max conc.) R. Vaillon et al. JNES 2018, 06/28/2018 3

4 Solar/Thermo-photovoltaics Thermophotovoltaics WASTE HEAT Irradiation spectrum [0.3-15] microns tunable emission where the cell is the most efficient PV cell K emitter W~p sr cooling system q bb (T e = K)= kw m -2 PV cell materials mostly compounds from the III-V group (In, As, Ga, Sb, ) Best (research) conversion efficiencies % [limited data!] bandgap E g ~ [ ] ev Dupré et al., Springer, 2017 Max: Carnot efficiency (T R. Vaillon et al. JNES 2018, 06/28/2018 e =2000 K & T c =300K: 85%) 4

5 Thermophotovoltaics Journal articles over the years Web of Science (topic or title contains thermophotovoltaic* ) ( =3.7%) 5 (at least one co-author with a French affiliation) 11 5 ( = 4.5%) ( Niche ) ? growth factor=6.9 (all=1.66) Ups and downs. Clear up since 2006 R. Vaillon et al. JNES 2018, 06/28/2018 5

6 Solar thermophotovoltaics Concept concentration absorber emitter Advantage: spectral tuning of radiation emitted toward the cell to maximize efficiency Practical implementation in the lab PV cell cooling system MIT device Max. theoretical efficiency Complex device, C=46.200, T e =2500 K & T c =300K: 85.4% Harder & Würfel, SST, 2003 Planar device, C=4.4, T e =1060 K & T c =300K: 45.3% Datas & Algora, PIP, 2013 Best (research) efficiency 6.8% Biermann et al., Nature Energy, 2016 Promising but many challenges to overcome R. Vaillon et al. JNES 2018, 06/28/2018 6

7 Solar thermophotovoltaics Key challenges Losses Research & technological needs photonics high-temperature material science thermal radiation transfer low-bandgap semiconductor material science electrical engineering Lenert et al., Nature Energy, 2014 thermal insulation / cooling Many challenges: multi- and interdisciplinary solutions R. Vaillon et al. JNES 2018, 06/28/2018 7

8 Solar thermophotovoltaics Emittance Sample results Univ. Tohoku device Absorber-emitter design Collaboration: Univ. Tohoku - CETHIL Emittance nm 10 nm 190 nm Absorptance Optimum 75 nm 10 nm Simulation Measurement 70 nm M S Shimizu et al., J. Photon. Energy, 2015 Kohiyama, et al., Applied Phys. Express, Wavelength [ m] Efficiency = 5.1% m Wavelength [ m] ( m) Blandre et al., Optics Express, 2018 Material science and thermal radiation design R. Vaillon et al. JNES 2018, 06/28/2018 8

9 Solar thermophotovoltaics Sample results B.S. senior design project at the University of Utah 5 students x 8 h x 32 weeks Collaboration: Univ. Utah - CETHIL Nice educational design project requiring multidisciplinary skills R. Vaillon et al. JNES 2018, 06/28/2018 9

10 Thermionic-thermophotovoltaic devices Concept emitter PV cell cathode Thermionic enhancement e- anode cooling system Datas, Applied Phys. Letters, 2016 Enhanced output voltage and grid-less front contact R. Vaillon et al. JNES 2018, 06/28/

11 Thermionic-thermophotovoltaic devices Key challenges small distance & vacuum d TPV cell - low workfunction - hole Datas, Applied Phys. Letters, 2016 extra voltage emitter / cathode anode Challenges: low workfunction coatings, small-gaps to reduce the space-charge R. Vaillon et al. JNES 2018, 06/28/

12 Thermionic-thermophotovoltaic devices Ongoing research LaB 6 (lanthanum hexaboride) Sample results Collaboration: IES Madrid - CETHIL Radiation electrical simulations spectral radiation flux absorbed by the receiver PV cell substrate BaF 2 (barium fluoride) useless for TPV angular frequency (10 15 rad/s) bandgap of the PV cell Materials to be found to optimize both thermionic and thermophotovoltaic conversions R. Vaillon et al. JNES 2018, 06/28/

13 Near-field thermophotovoltaic devices Concept Near-field radiation effects experimentally observed multiple times Thermal conductance (nw K -1 ) Advantage: additional contribution of the evanescent waves emitter PV cell cooling system Pan et al., IEEE TED, 2000 d < l Wien (10 m at 300 K) ~ x d (nm) Whale & Cravhalo, IEEE TEC, 2002 Song et al., Nature Nanotechnology, 2016 See also Bernardi et al., Nature Communications, 2016 Theoretically predicted huge near-field enhancements of electrical power R. Vaillon et al. JNES 2018, 06/28/

14 Current ( A) Near-field thermophotovoltaic devices Key challenges Experiments First (inconclusive attempt) DiMatteo et al., PRL, 2001 large emitter temperature Very recent breakthrough Fiorino et al., Nature Nanotechnology, 2018 emitter building a submicron gap PV cell cooling system efficient low band-gap PV cell in near-field illumination conditions ~ x40 Voltage (mv) Huge challenges, recent breakthrough, lot of room for improvement R. Vaillon et al. JNES 2018, 06/28/

15 Near-field thermophotovoltaic devices P(low injection)/ P(high injection) Sample results Radiative-electrical design CETHIL High-injection effects? p-on-n GaSb cell Collaboration: Univ. Utah - CETHIL External luminescence in devices Optimum doping of the p-doped layer (N a ) is function of emitter-cell distance (d) and cell top surface passivation Blandre et al., Sci. Reports, 2017 Radiative recombination/total recombination (performances of the PV cell) increases in the near-field DeSutter et al., PR Applied, 2017 Specific design of the PV cell according to near-field radiation conditions R. Vaillon et al. JNES 2018, 06/28/

16 Near-field thermophotovoltaic devices Ongoing research Collaboration: CETHIL IES Montpellier resistive wire to heat the sphere Scanning Thermal Microscopy (SThM) probe D ~ m T e [300 K K] InSb PV cell E g = K cooling system d from few nm to 5 m T c = 77 K Micro-scale lab experiment with a spherical emitter and a very low bandgap cell at around 77 K Lucchesi et al., Poster JNES, 2018 R. Vaillon et al. JNES 2018, 06/28/

17 Near-field thermophotovoltaic devices Ongoing research I (A) Collaboration: Univ. Utah - CETHIL - IES Madrid d, down to 100 nm!! emitter A, area of the cell free of contacts front contacts ~200 nm A = 1 x 1 mm 2 without with R ls I (A) with without R ls - - holes electrons V (V) p-on-n InAs cell d = 100 nm A = 100 x 100 m 2 V (V) back contacts Technological issues with front contacts because of high currents and lateral series resistance (R ls ) R. Vaillon et al. JNES 2018, 06/28/2018 Milovich et al., in preparation,

18 A chart for TPV devices? Conclusions Solar Thermophotovoltaics NF-Thermophotovoltaics IES-UPM MIT MIT (6.8%) U. Virginia U. Michigan (0.02%) Best research TPV device power outputs? R. Vaillon et al. JNES 2018, 06/28/

19 Conclusions Conclusions Key challenges require expertise in A picture speaks a thousand words thermal radiation / photonics semiconductor material science low-bandgap PV cell design, fabrication & characterization thermal insulation nanoscale device fabrication () x 6.9?! Multi- & interdisciplinary research is required with international collaborations R. Vaillon et al. JNES 2018, 06/28/

20 Further readings and acknowledgments Conclusions Further details on our recent results Blandre et al., Optics Express, 2018 Datas, APL, 2016 DeSutter, Vaillon, Francoeur, Phys. Rev. Applied, 2017 Blandre, Chapuis, Vaillon, Sci. Reports, 2017 Lucchesi et al., poster, JNES 2018 Acknowledgements DEMO-NFR-TPV (CETHIL IES Montpellier) AMADEUS (IES Madrid) Career Award (Univ. Utah) Merci pour votre attention R. Vaillon et al. JNES 2018, 06/28/