{Reference Type}: Journal Article {Title}: Mixed 2D-Dion–Jacobson/3D Sn-Pb alloyed perovskites for efficient photovoltaic solar devices {Author}: Lu, Zhili; Li, Chaohui; Lai, Hongwei; Zhou, Xinming; Wang, Chunfeng; Liu, Xianhu; Guo, Fei; Caofeng, Pan {Journal}: Nano Research {ISBN/ISSN}: 1998-0124 {Year}: 2023 {Volume}: 16 {Issue}: 2 {Pages}: 3142-3148 {DOI}: 10.1007/s12274-022-4894-1 {Keywords}: solar cells {Keywords}: Sn-Pb perovskite {Keywords}: narrow bandgap {Keywords}: Dion–Jacobson perovskite {Keywords}: two-dimensional (2D)/three-dimensional (3D) {Abstract}: Tin-lead (Sn-Pb) alloyed perovskites with tunable bandgaps hold great potential for constructing highly efficient single-junction and tandem photovoltaic devices. However, the efficiency and stability of Sn-Pb perovskite solar cells (PSCs) are greatly hampered by severe nonradiative recombination due to the easy oxidation of Sn(II). In this work, we report the construction of mixed dimensional two-dimensional (2D) Dion–Jacobson (DJ) and three-dimensional (3D) perovskites to improve the efficiency and stability of Sn-Pb alloyed PSCs. Introducing a small amount of 1,4-butanediammonium diiodide as spacer cations of DJ perovskites into precursor, the prepared mixed dimensional Sn-Pb alloyed perovskites exhibit reduced trap-state density due to the passivation of 2D DJ perovskites. As a result, nonradiative charge recombination is greatly suppressed. The prepared Sn-Pb alloyed PSCs based on 2D-DJ/3D heterojunction deliver a power conversion efficiency of 19.02% with an impressive fill factor of 80%. As well, improved device stability is realized due to the presence of DJ perovskites which serves as a protection barrier against oxidation and water invasion. {URL}: https://www.sciopen.com/article/10.1007/s12274-022-4894-1 {Language}: en