| Autor: |
C Ossig, N Pyrlik, R Carron, G Fevola, S Patjens, C Strelow, J Flügge, A Kolditz, J Siebels, J Garrevoet, K Spiers, M Seyrich, D Brückner, J Hagemann, F Seiboth, A Schropp, G Falkenberg, A Mews, C G Schroer, T Kipp, M E Stuckelberger |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
Journal of Physics: Energy. 4:045007 |
| ISSN: |
2515-7655 |
| Popis: |
Cost efficiency and defect passivation are the two major challenges that thin-film solar cells have to overcome for economic competitiveness. For Cu(In,Ga)Se 2 solar cells, the first is addressed by an increase of the Ga/In ratio, which widens the bandgap favorably for tandem applications and reduces the requirement of costly, rare In. The second is addressed by heavy alkali post-deposition treatments. However, the maximum device efficiency is typically achieved with a comparably low Ga/In ratio, which is in contrast to the economic interest of a higher Ga/In ratio and makes it paramount to identify, understand and mitigate the sources of local underperformance in Ga-rich cells. In this work, we investigate a series of Cu(In,Ga)Se 2 cells with varying Ga/In concentration in the absorber, using multi-modal scanning x-ray microscopy. In particular, we analyze differences in chemical composition and electrical performance on the nanoscale, with a focus on the effect of Rb. We find that In-rich cells show, along with a greater overall performance, a more homogeneous distribution of the nanoscale performance compared to the Ga-rich cells. Our analysis on Rb suggests that this effect is due to a more effective passivation of structural defects in the absorbers, i.e. voids and grain boundaries. These results shine light on the causes of the superiority of Ga-poor/In-rich absorbers and substantiate the trend to higher defect density for Ga-rich absorbers. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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