Compositional engineering of tin-lead halide perovskites for efficient and stable low band gap solar cells
| Autor: | Aslihan Babayigit, Hans-Gerd Boyen, Aryeh Gold-Parker, Tomas Leijtens, Rohit Prasanna, Michael D. McGehee, Bert Conings, Michael F. Toney |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Tandem Band gap business.industry Halide chemistry.chemical_element 02 engineering and technology Carrier lifetime equipment and supplies 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention chemistry law Electrode Solar cell Optoelectronics 0210 nano-technology business Tin Perovskite (structure) |
| Zdroj: | 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC). |
| DOI: | 10.1109/pvsc.2018.8547344 |
| Popis: | Tin-lead halide perovskites show promise as low- band gap absorbers to enable efficient all-perovskite tandem solar cells. While they have reached high efficiencies in single junction and in tandem solar cells, tin-containing perovskites face unique challenges- such as a tendency to degrade by oxidation of tin and sometimes very short carrier lifetimes that limit diffusion lengths. We map oxidation stability and important optoelectronic properties- band gap, carrier lifetime, and solar cell performance - across a wide range of compositions varying the A-site cation and the tin:lead ratio at the B-site. We identify mechanisms by which composition tunes the band gap in ways distinct from what has been reported for pure lead-based perovskites. We show that alloying tin with lead changes the mechanism by which tin is oxidized to a pathway that is relatively unfavourable. This significantly stabilizes the perovskite toward oxidation. Using a low band gap perovskite absorber, we demonstrate a 17.8% efficient single junction solar cell. Further, by employing a sputtered ITO top electrode, we demonstrate continuous operation of a solar cell in air with only a small drop in efficiency that is reversible upon storage in the dark This work creates a set of guiding principles to intelligently choose the best compositions for making efficient and stable solar cells based on tin-containing low band gap perovskites. |
| Databáze: | OpenAIRE |
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