Lead halide perovskites are among the most exciting classes of optoelectronic materials due to their unique ability to form high-quality crystals with tunable bandgaps in the visible and near-infrared using simple solution precipitation reactions. This facile crystallization is driven by their ionic nature; just as with other salts, it is challenging to form amorphous halide perovskites, particularly in thin-film form where they can most easily be studied. Here, rapid desolvation promoted by the addition of acetate precursors is shown as a general method for making amorphous lead halide perovskite films with a wide variety of compositions, including those using common organic cations (methylammonium and formamidinium) and anions (bromide and iodide). By controlling the amount of acetate, it is possible to tune from fully crystalline to fully amorphous films, with an interesting intermediate state consisting of crystalline islands embedded in an amorphous matrix. The amorphous lead halide perovskite has a large and tunable optical bandgap. It improves the photoluminescence quantum yield and lifetime of incorporated crystalline perovskite, opening up the intriguing possibility of using amorphous perovskite as a passivating contact, as is currently done in record efficiency silicon solar cells.
Bibliographical noteFunding Information:
This work is part of the research program AMOLF, which is partly funded by the Dutch Research Council (NWO). Via our membership of the UK's HEC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202), this work used the ARCHER UK National Supercomputing Service ( http://www.archer.ac.uk ). This material is based upon work supported by the National Science Foundation under Grant No. DMR‐1848371. Use of the Center for Nanoscale Materials and the Advanced Photon Source, both Office of Science user facilities, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE‐AC02‐06CH11357. PM, SRE and RMAH acknowledge financial support by the LINK program of the Dutch province of Limburg and Interreg V‐A EMR and the Netherlands Ministry of Economic Affairs within the “Interreg Euro‐Maas‐Rijn” project (project number EMR23).
© 2021 The Authors. Advanced Functional Materials published by Wiley-VCH GmbH.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics