친환경 Pb-Free 페로브스카이트 태양전지를 위한 비스무스 기반의 무기 박막 최적화 연구

Abstract

Perovskite solar cells have received increasing attention in recent years because of their outstanding powerconversion efficiency (exceeding 22%). However, they typically contain toxic Pb, which is a limiting factor forindustrialization. We focused on preparing Pb-free perovskite films of Ag-Bi-I trivalent compounds. Perovskite thin films withimproved optical properties were obtained by applying an anti-solvent (toluene) washing technique during the spin coating ofperovskites. In addition, the surface condition of the perovskite film was optimized using a multi-step thermal annealingtreatment. Using the optimized process parameters, AgBi2I7 perovskite films with good absorption and improved planar surfacetopography (root mean square roughness decreased from 80 to 26 nm) were obtained. This study is expected to open up newpossibilities for the development of high performance AgBi2I7 perovskite solar cells for applications in Pb-free energyconversion devices.