Quantum Dynamics Simulations on the Adsorption Mechanism of Reducing and Oxidizing Gases on the CH₃NH₃PbI₃ Surface

Abstract

Existing experiments have revealed that methylammonium lead iodide (MAPbI 3 or CH 3 NH 3 PbI 3 ) materials show favorable gas-sensing properties to reducing gas NH 3 and oxidizing gases O 2 and O 3 . The first step to effective gas-sensing by using semiconductor materials for gas-sensing applications is to recognize a target gas through gas-solid interaction. To explore the sensing mechanisms of perovskite materials to different oxidizing and reducing gases, the changes of skeleton structures of MAPbI 3 in reducing gas NH 3 and oxidizing gases O 2 and O 3 , adsorption energy, and charge transfer between gases and semiconductors are investigated through large-scale quantum dynamics simulations. By using three adsorption models, the differences and similarities of adsorption mechanisms of MAPbI 3 for gases NH 3 , O 2 , and O 3 are illustrated. These adsorption mechanisms are expected to provide new ideas for developing innovative sensing elements made of perovskite materials with stronger stability, high sensitivity, and high selectivity.

High‐Performance Optoelectronic Gas Sensing Based on All‐Inorganic Mixed‐Halide Perovskite Nanocrystals with Halide Engineering

“…Central metal ion, which is Pb 2+ in all‐inorganic halide perovskite, is the main active site for interacting with the gas molecules. [ 64 ] In one representative study, it was confirmed that more Pb cations existing on the surface can enhance the adsorption of NO 2 molecules and their interaction with the sensing layer. [ 36 ] Therefore, the oxidation‐reduction properties of Pb can make a significant impact on the CsPbI 3 ‐NO 2 and CsPbBr 3 ‐NO 2 complexes.…”