%0 Journal Article
%A Ünlü, Feray
%A Kulkarni, Ashish
%A Lê, Khan
%A Bohr, Christoph
%A Bliesener, Andrea
%A Öz, Seren Dilara
%A Jena, Ajay Kumar
%A Ando, Yoichi
%A Miyasaka, Tsutomu
%A Kirchartz, Thomas
%A Mathur, Sanjay
%T Single- or double A-site cations in A3Bi2I9 bismuth perovskites: What is the suitable choice?
%J Journal of materials research
%V 36
%N 9
%@ 2044-5326
%C Cambridge [u.a.]
%I Cambridge Univ. Press
%M FZJ-2021-03133
%P 1794 - 1804
%D 2021
%X Investigations on the effect of single or double A-site cation engineering on the photovoltaic performance of bismuth perovskite-inspired materials (A3Bi2I9) are rare. Herein, we report novel single- and double-cation based bismuth perovskite-inspired materials developed by (1) completely replacing CH3NH3+ (methylammonium, MA+) in MA3Bi2I9 with various organic cations such as CH(NH2)2+ (formamidinium, FA+), (CH3)2NH2+ (dimethylammonium, DMA+), C(NH2)3+ (guanidinium, GA+) and inorganic cations such as cesium (Cs+), rubidium (Rb+), potassium (K+), sodium (Na+) and lithium (Li+) and (2) partially replacing MA+ with Cs+ in different stoichiometric ratios. Compared to single-cation based bismuth perovskite devices, the double-cation bismuth perovskite device showed an increment in the device power conversion efficiency (PCE) up to 1.5% crediting to the reduction in the bandgap. This is the first study demonstrating double-cation based bismuth perovskite showing bandgap reduction and increment in device efficiency and opens up the possibilities towards compositional engineering for improved device performance.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000635073400001
%R 10.1557/s43578-021-00155-z
%U https://juser.fz-juelich.de/record/894258