High Current Density Sn-Based Perovskite Solar Cells via Enhanced Electron Extraction in Nanoporous Electron Transport Layers

• DOI: 10.1021/acsanm.0c02890
• Publication Date: 2020-11-11T21:12:06Z
• Authors: Yumi Miyamoto; Shohei Kusumoto; Tomoyasu Yokoyama; Yu Nishitani; Taisuke Matsui; Takashi Kouzaki; Ryosuke Nishikubo; Akinori Saeki; Yukihiro Kaneko
• Keywords: Nanoporous; Perovskite solar cell

Sn-based perovskite solar cells have attracted much attention as the lead-free next generation of cells. However, their efficiency is still low (∼12%). One reason that carrier diffusion length perovskites shorter than Pb-based perovskites. In this study, we investigated effects electron transport layer (ETL) structure, using a porous niobium oxide (Nb2O5) ETL to create highly efficient cell. We quantified structure on extraction by time-resolved microwave conductivity (TRMC) measurements. From TRMC and chemical analyses materials, determined with smaller pores extracts electrons more effectively from larger pores. To realize this, shortened distance photogenerated carriers must move for extraction, resulting in less recombination higher device performance. The small-pore (pore size: 5 nm) nanoporous cell exhibits highest level current density (24.0 mA cm–2) (7.0%) among n–i–p structured These results demonstrate importance structural design creating