Back-surface recombination, electron reflectors, and paths to 28% efficiency for thin-film photovoltaics: A CdTe case study

Duenow, Joel N.; Metzger, Wyatt K.

doi:10.1063/1.5063799

Title: Back-surface recombination, electron reflectors, and paths to 28% efficiency for thin-film photovoltaics: A CdTe case study

Journal Article · 31 January 2019 · Journal of Applied Physics

DOI: https://doi.org/10.1063/1.5063799 · OSTI ID:1494117

Duenow, Joel N. ^[1]; Metzger, Wyatt K. ^[1]

National Renewable Energy Lab. (NREL), Golden, CO (United States)

As thin-film and silicon solar technologies mature, questions emerge about the upper bounds of thin-film solar performance and realistic experimental paths to reach them. Directions include increasing absorber hole density and bulk lifetime, improving the junction interface, reducing back-surface recombination, and implementing a back-surface electron reflector. Textbook solutions of idealized p-n junctions create a powerful conceptualization of solar cells as predominantly minority-carrier-driven devices. We demonstrate that thin films are distinct, and models often fail to capture the important role of majority-carrier lifetime, leading to contradictions with lifetime measurements and overestimates of potential device improvement from back-surface passivation and/or reflectors. Furthermore, we identify methods to probe majority-carrier lifetime and re-examine the degree to which back-surface passivation and electron reflectors can increase efficiency for a range of common thin-film interface and absorber properties, using current and emerging CdTe technology as an example. Here, the results indicate that a practical approach is to focus first on improving front-interface recombination velocity and the absorber properties, and then on implementing the back-surface passivation or reflector, which can ultimately allow thin-film solar technology to reach 28% efficiency.

View Accepted Manuscript (DOE)

Cite

Export

Save

Research Organization:: National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Sponsoring Organization:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)

Grant/Contract Number:: AC36-08GO28308

OSTI ID:: 1494117

Report Number(s):: NREL/JA--5K00-73045

Journal Information:: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 125; ISSN 0021-8979

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

References (33)

Obtaining Large Columnar CdTe Grains and Long Lifetime on Nanocrystalline CdSe, MgZnO, or CdS Layers Amarasinghe, Mahisha; Colegrove, Eric; Moseley, John Advanced Energy Materials, Vol. 8, Issue 11 https://doi.org/10.1002/aenm.201702666	journal	January 2018
Solar cell efficiency tables (version 52) Green, Martin A.; Hishikawa, Yoshihiro; Dunlop, Ewan D. Progress in Photovoltaics: Research and Applications, Vol. 26, Issue 7 https://doi.org/10.1002/pip.3040	journal	June 2018
Carrier generation-recombination in the space-charge region of an asymmetrical p-n junction Choo, S. C. Solid-State Electronics, Vol. 11, Issue 11 https://doi.org/10.1016/0038-1101(68)90129-9	journal	November 1968
Modelling polycrystalline semiconductor solar cells Burgelman, M.; Nollet, P.; Degrave, S. Thin Solid Films, Vol. 361-362 https://doi.org/10.1016/S0040-6090(99)00825-1	journal	February 2000
Energy-band barrier to improve open-circuit voltage of CdTe solar cells Hsiao, Kuo-Jui Solar Energy Materials and Solar Cells, Vol. 120 https://doi.org/10.1016/j.solmat.2013.10.015	journal	January 2014
Co-sublimation of CdSexTe1−x layers for CdTe solar cells Swanson, Drew E.; Sites, James R.; Sampath, Walajabad S. Solar Energy Materials and Solar Cells, Vol. 159 https://doi.org/10.1016/j.solmat.2016.09.025	journal	January 2017
Strategies to increase CdTe solar-cell voltage Sites, James; Pan, Jun Thin Solid Films, Vol. 515, Issue 15, p. 6099-6102 https://doi.org/10.1016/j.tsf.2006.12.147	journal	May 2007
CdTe solar cells with open-circuit voltage breaking the 1 V barrier Burst, J. M.; Duenow, J. N.; Albin, D. S. Nature Energy, Vol. 1, Issue 3 https://doi.org/10.1038/nenergy.2016.15	journal	February 2016
Monocrystalline CdTe solar cells with open-circuit voltage over 1 V and efficiency of 17% Zhao, Yuan; Boccard, Mathieu; Liu, Shi Nature Energy, Vol. 1, Issue 6 https://doi.org/10.1038/nenergy.2016.67	journal	May 2016
Cu2ZnSnS4 solar cells with over 10% power conversion efficiency enabled by heterojunction heat treatment Yan, Chang; Huang, Jialiang; Sun, Kaiwen Nature Energy, Vol. 3, Issue 9 https://doi.org/10.1038/s41560-018-0206-0	journal	July 2018
Overcoming Carrier Concentration Limits in Polycrystalline CdTe Thin Films with In Situ Doping McCandless, Brian E.; Buchanan, Wayne A.; Thompson, Christopher P. Scientific Reports, Vol. 8, Issue 1 https://doi.org/10.1038/s41598-018-32746-y	journal	September 2018
Time-resolved photoluminescence studies of CdTe solar cells Metzger, W. K.; Albin, D.; Levi, D. Journal of Applied Physics, Vol. 94, Issue 5, p. 3549-3555 https://doi.org/10.1063/1.1597974	journal	September 2003
Hole current impedance and electron current enhancement by back-contact barriers in CdTe thin film solar cells Pan, Jun; Gloeckler, Markus; Sites, James R. Journal of Applied Physics, Vol. 100, Issue 12 https://doi.org/10.1063/1.2400799	journal	December 2006
Long lifetimes in high-efficiency Cu(In,Ga)Se2 solar cells Metzger, Wyatt K.; Repins, Ingrid L.; Contreras, Miguel A. Applied Physics Letters, Vol. 93, Issue 2 https://doi.org/10.1063/1.2957983	journal	July 2008
Single-crystal CdTe solar cells with V _oc greater than 900 mV Duenow, J. N.; Burst, J. M.; Albin, D. S. Applied Physics Letters, Vol. 105, Issue 5 https://doi.org/10.1063/1.4892401	journal	August 2014
Enhancing the photo-currents of CdTe thin-film solar cells in both short and long wavelength regions Paudel, Naba R.; Yan, Yanfa Applied Physics Letters, Vol. 105, Issue 18 https://doi.org/10.1063/1.4901532	journal	November 2014
Intrinsic surface passivation of CdTe Reese, M. O.; Perkins, C. L.; Burst, J. M. Journal of Applied Physics, Vol. 118, Issue 15 https://doi.org/10.1063/1.4933186	journal	October 2015
Carrier density and lifetime for different dopants in single-crystal and polycrystalline CdTe Burst, James M.; Farrell, Stuart B.; Albin, David S. APL Materials, Vol. 4, Issue 11 https://doi.org/10.1063/1.4966209	journal	November 2016
The roles of carrier concentration and interface, bulk, and grain-boundary recombination for 25% efficient CdTe solar cells Kanevce, A.; Reese, M. O.; Barnes, T. M. Journal of Applied Physics, Vol. 121, Issue 21 https://doi.org/10.1063/1.4984320	journal	June 2017
High growth rate hydride vapor phase epitaxy at low temperature through use of uncracked hydrides Schulte, Kevin L.; Braun, Anna; Simon, John Applied Physics Letters, Vol. 112, Issue 4 https://doi.org/10.1063/1.5013136	journal	January 2018
Recombination velocity less than 100 cm/s at polycrystalline Al ₂ O ₃ /CdSeTe interfaces Kuciauskas, Darius; Kephart, Jason M.; Moseley, John Applied Physics Letters, Vol. 112, Issue 26 https://doi.org/10.1063/1.5030870	journal	June 2018
Experimental and theoretical comparison of Sb, As, and P diffusion mechanisms and doping in CdTe Colegrove, E.; Yang, J-H; Harvey, S. P. Journal of Physics D: Applied Physics, Vol. 51, Issue 7 https://doi.org/10.1088/1361-6463/aaa67e	journal	January 2018
Electron-Hole Recombination in Germanium Hall, R. N. Physical Review, Vol. 87, Issue 2 https://doi.org/10.1103/PhysRev.87.387	journal	July 1952
Statistics of the Recombinations of Holes and Electrons Shockley, W.; Read, W. T. Physical Review, Vol. 87, Issue 5 https://doi.org/10.1103/PhysRev.87.835	journal	September 1952
Analysis of charge separation dynamics in a semiconductor junction Metzger, W. K.; Ahrenkiel, R. K.; Dashdorj, J. Physical Review B, Vol. 71, Issue 3 https://doi.org/10.1103/PhysRevB.71.035301	journal	January 2005
CdTe Solar Cells at the Threshold to 20% Efficiency Gloeckler, M.; Sankin, I.; Zhao, Z. IEEE Journal of Photovoltaics, Vol. 3, Issue 4 https://doi.org/10.1109/JPHOTOV.2013.2278661	journal	October 2013
Surface Passivation of CdTe Single Crystals Reese, Matthew O.; Burst, James M.; Perkins, Craig L. IEEE Journal of Photovoltaics, Vol. 5, Issue 1 https://doi.org/10.1109/JPHOTOV.2014.2362298	journal	January 2015
Relationship of Open-Circuit Voltage to CdTe Hole Concentration and Lifetime Duenow, Joel N.; Burst, James M.; Albin, David S. IEEE Journal of Photovoltaics, Vol. 6, Issue 6 https://doi.org/10.1109/JPHOTOV.2016.2598260	journal	November 2016
Polycrystalline CdSeTe/CdTe Absorber Cells With 28 mA/cm ² Short-Circuit Current Munshi, Amit H.; Kephart, Jason; Abbas, Ali IEEE Journal of Photovoltaics, Vol. 8, Issue 1 https://doi.org/10.1109/JPHOTOV.2017.2775139	journal	January 2018
Sputter-Deposited Oxides for Interface Passivation of CdTe Photovoltaics Kephart, Jason M.; Kindvall, Anna; Williams, Desiree IEEE Journal of Photovoltaics, Vol. 8, Issue 2 https://doi.org/10.1109/JPHOTOV.2017.2787021	journal	March 2018
Influence of CdTe Deposition Temperature and Window Thickness on CdTe Grain Size and Lifetime After CdCl 2 Recrystallization Amarasinghe, Mahisha; Sivananthan, Siva; Metzger, Wyatt K. IEEE Journal of Photovoltaics, Vol. 8, Issue 2 https://doi.org/10.1109/JPHOTOV.2018.2790701	journal	March 2018
Carrier Generation and Recombination in P-N Junctions and P-N Junction Characteristics Sah, Chih-tang; Noyce, Robert; Shockley, William Proceedings of the IRE, Vol. 45, Issue 9 https://doi.org/10.1109/JRPROC.1957.278528	journal	September 1957
Electron-Hole Diffusion Lengths Exceeding 1 Micrometer in an Organometal Trihalide Perovskite Absorber Stranks, S. D.; Eperon, G. E.; Grancini, G. Science, Vol. 342, Issue 6156, p. 341-344 https://doi.org/10.1126/science.1243982	journal	October 2013

Cited By (3)

Scalable ultrafast epitaxy of large-grain and single-crystal II-VI semiconductors Colegrove, Eric; Albin, David S.; Moutinho, Helio R. Scientific Reports, Vol. 10, Issue 1 https://doi.org/10.1038/s41598-020-59083-3	journal	February 2020
Exceeding 20% efficiency with in situ group V doping in polycrystalline CdTe solar cells Metzger, W. K.; Grover, S.; Lu, D. Nature Energy, Vol. 4, Issue 10 https://doi.org/10.1038/s41560-019-0446-7	journal	August 2019
Light-trapping schemes for silicon thin-film solar cells via super-quadratic subwavelength gratings Chen, Ke; Wu, Rui; Zheng, Hongmei Applied Optics, Vol. 58, Issue 31 https://doi.org/10.1364/ao.58.008702	journal	January 2019

Similar Records

Transparent MgO for Back-Contact Passivation of CdTe-Based Solar Cells

Conference · 2021 · OSTI ID:1823782

Pandey, Ramesh; Shah, Akash; Munshi, Amit; +4 more

CdSexTe1-x /CdTe Devices With Reduced Interface Recombination Through Novel Back Contacts and Doping Strategies

Conference · 2020 · OSTI ID:1670797

Danielson, Adam; Kuciauskas, Darius; Reich, Carey; +7 more

Exceeding 200 ns Lifetimes in Polycrystalline CdTe Solar Cells

Journal Article · 2021 · Solar RRL · OSTI ID:1788433

Ablekim, Tursun; Duenow, Joel N.; Perkins, Craig L.; +10 more

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
CdTe
back surface recombination
electron reflector
lifetime

Title: Back-surface recombination, electron reflectors, and paths to 28% efficiency for thin-film photovoltaics: A CdTe case study

Citation Formats

References (33)

Cited By (3)

Similar Records

Related Subjects