2025 - Sustainable Industrial Processing Summit
SIPS2025 Volume 9. Intl. Symp on Advanced Materials, Biomaterials, Manufacturing and Quasi-Crystals
| Editors: | F. Kongoli, F. Marquis, N. Chikhradze, T. Prikhna, M. Bechelany, H. Oudadesse, K. Pramanik, R. Das, E. Suhir |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2025 |
| Pages: | 282 pages |
| ISBN: | 978-1-998384-54-9 (CD) |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
CD shopping page
16% EFFICIENT LEAD-FREE PEROVSKITE SOLAR CELLSACHIEVED BY DEFECT PASSIVATION AND ENERGY LEVEL ADJUSTMENT
Yuedong Shi1;1SHANGHAITECH UNIVERSITY, Shanghai, China;
Type of Paper: Regular
Id Paper: 274
Topic: 43
Abstract:
As a new class of semiconducting materials with excellent optoelectronic properties, metal halide perovskites have been applied in various fields such as solar cells, photodetectors, and electroluminescence. However, the toxicity of the lead element contained in these materials limits their application scenarios. Tin, a low-toxic element in the same main group as lead, is considered the most suitable alternative to lead. However, the performance of tin perovskite materials is currently far inferior to lead-containing materials, especially in terms of the short carrier lives and low open-circuit voltages of photovoltaic devices. Current research community generally attribute these phenomena to the material defects of tin perovskites, but the nature and regulation of these defects remain obscure. Under the guidance of theory, we have systematically studied this issue for tin perovskites from both aspects of bulk and surfaces, and prepared a series of high-quality single crystal and thin film samples. We directly characterized the types of defects, their concentrations and influence on semiconductor properties, revealing that the dominant defects in tin perovskites are not directly caused by oxidation of Sn2+. We found that substituted thiourea molecules as Lewis-base ligands can deactivate the Sn2+ 5s electron pair and create an appropriate intermediate phase structure, thereby slowing down the crystallization rate, inhibiting surface and bulk defects of the crystal, and obtaining high-quality thin films. On the other hand, by decorating the thin-film surfaces with molecular dipoles but not changing the bandgap of perovskite layer, we elevated its conduction band minimum (CBM) to better match the energy level of the electron transport material (ETM). The above measures have rendered thin films of tin perovskite with charge carrier lifetimes longer than 0.5 μs and diffusion lengths on the micrometer scale, and boosted the open-circuit voltage of solar cell devices to 1.0 V (only ~0.1 V loss), approaching the level of lead-containing materials. The energy conversion efficiency reached 16%, setting a new performance record for lead-free perovskite solar cells. Their stabilities are also significantly enhanced, demonstrating a promising application prospect.