A Dual‐Retarded Reaction Processed Mixed‐Cation Perovskite Layer for High‐Efficiency Solar Cells. (28th January 2019)

• Record Type: Journal Article
• Authors: Mali, Sawanta S.; Patil, Jyoti V.; Kim, Hyungjin; Kim, HyunHoon; Hong, Chang Kook
• Is Part Of: Advanced functional materials. Volume 29:Number 15(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-01-28
• Subjects: >20% PCE -- dual retarding process -- mixed‐cation mixed halide -- perovskite solar cells; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201807420
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Mixed‐cation perovskite solar cells (PSCs) have become of enormous interest because of their excellent efficiency, which is now crossing 23.7%. Their broader absorption, relatively high stability with low fabrication cost compared to conventional single phase ABX3 perovskites (where A: organic cation; B: divalent metal ion; and X: halide anion) are key properties of mixed‐halide mixed‐cation perovskites. However, the controlling reaction rate and formation of extremely dense, textured, smooth, and large grains of perovskite layer is a crucial task in order to achieve highly efficient PSCs. Herein, a new simple dual‐retarded reaction processing (DRP) method is developed to synthesize a high‐quality mixed‐cation (FAPbI3 )0.85 (MAPbBr3 )0.15 (where MAPbBr3 stands for methylammonium lead bromide and FAPbI3 stands for formamidinium lead iodide) perovskite thin film via intermediate phase and incorporation of nitrogen‐doped reduced graphene oxide (N‐rGO). The reaction rate is retarded via two steps: first the formation of intermediate phase and second the interaction of the nitrogen groups on N‐rGO with hydrogen atoms from formamidinium cations. This DRP process allows for the fabrication of PSCs with maximum conversion efficiency higher than 20.3%. Abstract : Controlling the retarding reaction process enhances perovskite crystal growth, resulting in >20% efficiency. The dual retarding process enables large perovskite thin film grain size, which facilitates enhanced photovoltaic performance.