Journal Article

Light-activated interlayer contraction in two-dimensional perovskites for high-efficiency solar cells

Even, Jacky, Alam, Muhammad A., Hoffman, Justin M., Mohite, Aditya D., Wang, Yafei, Kanatzidis, Mercouri G., Hou, Jin, Strzalka, Joseph, Essman, Joseph, Traore, Boubacar, Li, Wenbin, Zhang, Hao, Asadpour, Reza, Blancon, Jean-Christophe, Sidhik, Siraj, Crochet, Jared J., Tsai, Esther, Spanopoulos, Ioannis, Fehr, Austin, Katan, Claudine

2022

Overview

Understanding and tailoring the physical behaviour of halide perovskites under practical environments is critical for designing efficient and durable optoelectronic devices. Here, we report that continuous light illumination leads to >1% contraction in the out-of-plane direction in two-dimensional hybrid perovskites, which is reversible and strongly dependent on the specific superlattice packing. X-ray photoelectron spectroscopy measurements show that constant light illumination results in the accumulation of positive charges in the terminal iodine atoms, thereby enhancing the bonding character of inter-slab I–I interactions across the organic barrier and activating out-of-plane contraction. Correlated charge transport, structural and photovoltaic measurements confirm that the onset of the light-induced contraction is synchronized to a threefold increase in carrier mobility and conductivity, which is consistent with an increase in the electronic band dispersion predicted by first-principles calculations. Flux-dependent space-charge-limited current measurement reveals that light-induced interlayer contraction activates interlayer charge transport. The enhanced charge transport boosts the photovoltaic efficiency of two-dimensional perovskite solar cells up to 18.3% by increasing the device’s fill factor and open-circuit voltage. Light-induced contraction in the out-of-plane direction in two-dimensional (2D) hybrid perovskites enables the realization of high-efficiency 2D perovskite solar cells.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 119/118 / 140/146 / 639/301/299/946 / 639/4077/4072/4062 / 639/766/1130/2800 / 639/925/357/404 / Carrier mobility / Charge transport / Chemical bonds / Chemical Sciences / Chemistry and Materials Science / Contraction / Devices for energy harvesting / Efficiency / First principles / Illumination / Interlayers / Iodine / Light / MATERIALS SCIENCE / Nanotechnology / Nanotechnology and Microengineering / Open circuit voltage / Optoelectronic devices / Optomechanics / Organic–inorganic nanostructures / Perovskites / Photoelectron spectroscopy / Photoelectrons / Photovoltaic cells / Photovoltaics / Physics / Solar cells / Superlattices