Understanding the Effect of Lead Iodide Excess on the Performance of Methylammonium Lead Iodide Perovskite Solar Cells
| Autor: | Zeeshan Ahmad, Rebecca A. Scheidt, Matthew P. Hautzinger, Kai Zhu, Matthew C. Beard, Giulia Galli |
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| Rok vydání: | 2022 |
| Předmět: |
Condensed Matter - Materials Science
Fuel Technology Renewable Energy Sustainability and the Environment Chemistry (miscellaneous) Materials Chemistry Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Energy Engineering and Power Technology Applied Physics (physics.app-ph) Physics - Applied Physics |
| Zdroj: | ACS Energy Letters. 7:1912-1919 |
| ISSN: | 2380-8195 |
| Popis: | The presence of unreacted lead iodide in organic-inorganic lead halide perovskite solar cells is widely correlated with an increase in power conversion efficiency. We investigate the mechanism for this increase by identifying the role of surfaces and interfaces present between methylammonium lead iodide perovskite films and excess lead iodide. We show how type I and II band alignments arising under different conditions result in either passivation of surface defects or hole injection. Through first-principles simulations of solid-solid interfaces, we find that lead iodide captures holes from methylammonium lead iodide and modulates the formation of defects in the perovskite, affecting recombination. Using surface-sensitive optical spectroscopy techniques, such as transient reflectance and time-resolved photoluminescence, we show how excess lead iodide affects the diffusion and surface recombination velocity of charge carriers in methylammonium lead iodide films. Our coupled experimental and theoretical results elucidate the role of excess lead iodide in perovskite solar cells. 4 figures, 1 table, 21 pages + 13 pages of Supporting Information |
| Databáze: | OpenAIRE |
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