Back-Surface Passivation of CdTe Solar Cells Using Solution-Processed Oxidized Aluminum
| Autor: | Randy J. Ellingson, Adam B. Phillips, Michael J. Heben, Fadhil K. Alfadhili, Adam I Halaoui, Deng-Bing Li, Manoj K. Jamarkattel, Bhuiyan M. M. Anwar, Yanfa Yan, Geethika K. Liyanage, Corey R. Grice, Craig L. Perkins, Kamala Khanal Subedi |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Photoluminescence Dopant Passivation business.industry Open-circuit voltage 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Cadmium telluride photovoltaics 0104 chemical sciences Photovoltaics Monolayer Optoelectronics General Materials Science Quantum efficiency 0210 nano-technology business |
| Zdroj: | ACS Applied Materials & Interfaces. 12:51337-51343 |
| ISSN: | 1944-8252 1944-8244 |
| Popis: | Although back-surface passivation plays an important role in high-efficiency photovoltaics, it has not yet been definitively demonstrated for CdTe. Here, we present a solution-based process, which achieves passivation and improved electrical performance when very small amounts of oxidized Al3+ species are deposited at the back surface of CdTe devices. The open circuit voltage (Voc) is increased and the fill factor (FF) and photoconversion efficiency (PCE) are optimized when the total amount added corresponds to ∼1 monolayer, suggesting that the passivation is surface specific. Addition of further Al3+ species, present in a sparse alumina-like layer, causes the FF and PCE to drop as the interface layer becomes blocking to current flow. The optimized deposit increases the average baseline PCE for both Cu-free devices and devices where Cu is present as a dopant. The greatest improvement is found when the Al3+ species are deposited prior to the CdCl2 activation step and Cu is employed. In this case, the best-cell efficiency was improved from 12.6 to 14.4%. Time-resolved photoluminescence measurements at the back surface and quantum efficiency measurements performed at the maximum power point indicate that the performance enhancement is due to a reduction in the interface recombination current at the back surface. |
| Databáze: | OpenAIRE |
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