Chemical sintering reduced grain boundary defects for stable planar perovskite solar cells. (February 2019)

• Record Type: Journal Article
• Authors: Xi, Jun; Xi, Kai; Sadhanala, Aditya; Zhang, Kelvin H.L.; Li, Guangru; Dong, Hua; Lei, Ting; Yuan, Fang; Ran, Chenxin; Jiao, Bo; Coxon, Paul R.; Harris, Christopher J.; Hou, Xun; Kumar, R. Vasant; Wu, Zhaoxin
• Is Part Of: Nano energy. Volume 56(2019)
• Page Start: 741
• Page End: 750
• Publication Date: 2019-02
• Subjects: Chemical sintering -- Perovskite -- Grain boundary disturbance -- Parasitic traps -- Urbach energy; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2018.11.021
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Organic–inorganic hybrid perovskite solar cells have attracted tremendous attention in photovoltaic research, but the presence of massive parasitic traps at the grain boundaries in perovskite films discourages efficient bimolecular recombination and carrier dynamics, which limits device performance and stability. Here we report a simple and fast chemical sintering protocol to substantially reduce grain boundary defects for as-formed films for different PbI2 -templated perovskite materials. With this method parasitic traps on grain boundaries are intrinsically reduced, featuring the Urbach energy reduced by 1.5 meV. For optimal photovoltaic devices, we demonstrate a planar solar cell with power conversion efficiency (PCE) of 19.68% which retains 80% of this efficiency over 720 h in ambient air without any encapsulation. These findings offer a widely applicable, versatile process to efficiently reduce grain boundary defects and will be of interest to many other film material systems afflicted by polydispersity and grain boundary disturbances. Graphical abstract: Highlights: A chemical sintering protocol to suppress grain boundary traps of perovskites. Reduced traps featuring Urbach Energy decreased by 1.5 meV. A mechanism of anion catalyzes rebuilding of lead halide template (ACRT). The highest PCE of 19.68%, remaining 80% in 720 h in ambient air.