Water as the Only Solvent for CsPbCl3 and NIR‐Emitting CsPbCl3:Yb3+ Films by Antisolvent‐Enhanced Crystallization in Aerosol‐Assisted Chemical Vapor Deposition

Abstract

AbstractCsPbX3 (X = Cl, Br, I) perovskites have emerged as promising materials for optoelectronic applications. However, thin film synthesis has essential issues such as chemical stability, toxicity, and processability. In this work, a green synthesis approach using water as the only solvent to deposit CsPbCl3 and CsPbCl3:Yb3+ films by aerosol assisted chemical vapor deposition technique under ambient atmospheric conditions, is proposed. X‐ray diffraction pattern and X‐ray photoelectron spectroscopy analysis confirm the phase purity and negligible degradation by using water during deposition. Moreover, CsPb2Cl5 secondary phase is detected as a substitution and anchoring doped mechanism response for doped materials. Additionally, green antisolvents (alcohols and propan‐2‐one) are used to assist the crystallization process; all the green antisolvents result in an increased substrate coverage, highlighting those with high boiling points and low heat of combustion that promote heterogeneous nucleation. As‐deposited films show a photoluminescent excitonic emission peak around 418 nm and an additional peak at 984 nm emission band associated with the Yb3+ infrared 2F5/2 to 2F7/2 transitions for doped materials. Near infra‐red photoluminescence emission is notably improved upon antisolvent assistance up to a threefold increase for ethanol, reaching a photoluminescence quantum yield of 33.94% at low Yb3+ concentration.