Enhanced Charge Transport by Incorporating Formamidinium and Cesium Cations into Two‐Dimensional Perovskite Solar Cells. (11th July 2019)

• Record Type: Journal Article
• Authors: Gao, Liguo; Zhang, Fei; Chen, Xihan; Xiao, Chuanxiao; Larson, Bryon W.; Dunfield, Sean P.; Berry, Joseph J.; Zhu, Kai
• Is Part Of: Angewandte Chemie. Volume 131:Number 34(2019)
• Page Start: 11863
• Page End: 11867
• Publication Date: 2019-07-11
• Subjects: Caesium -- Kationen -- Ladungstransport -- Perowskitphasen -- Solarzellen; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201905690
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Organic‐inorganic hybrid two‐dimensional (2D) perovskites ( n ≤5) have recently attracted significant attention because of their promising stability and optoelectronic properties. Normally, 2D perovskites contain a monocation [e.g., methylammonium (MA + ) or formamidinium (FA + )]. Reported here for the first time is the fabrication of 2D perovskites ( n =5) with mixed cations of MA +, FA +, and cesium (Cs + ). The use of these triple cations leads to the formation of a smooth, compact surface morphology with larger grain size and fewer grain boundaries compared to the conventional MA‐based counterpart. The resulting perovskite also exhibits longer carrier lifetime and higher conductivity in triple cation 2D perovskite solar cells (PSCs). The power conversion efficiency (PCE) of 2D PSCs with triple cations was enhanced by more than 80 % (from 7.80 to 14.23 %) compared to PSCs fabricated with a monocation. The PCE is also higher than that of PSCs based on binary cation (MA + ‐FA + or MA + ‐Cs + ) 2D structures. Abstract : Drei ist besser als eins : 2D‐Perowskite ( n =5) mit drei Kationen wurden hergestellt. Sie zeigen längere Trägerlebensdauer, größere Beweglichkeit und höhere Leitfähigkeit. Die Effizienz von 2D‐Perowskitsolarzellen (PSCs) mit drei Kationen ist um >80 % (von 7.80 zu 14.23 %) gegenüber PSCs mit einem Monokation erhöht. Sie ist auch höher als jene von PSCs auf Basis von 2D‐Strukturen binärer Kationen.