Large scale quantum dynamics investigations on the sensing mechanism of H₂O, acetone, NO₂ and O₃ adsorption on the (MA)₂Pb(SCN)₂I₂ surface

Abstract

The sensing mechanism of perovskite materials is described quantitively via bond breaking/formation and charge transfer analyses along with the dynamical processes.

Sensing Mechanism of H2O, NH3, and O2 on the Stability-Improved Cs2Pb(SCN)2Br2 Surface: A Quantum Dynamics Investigation

“…However, the weak Pb–I bonds in the structure are still the targets of oxidizing or reducing gases. It has been found that both the neutral H 2 O and oxidative gases (NO 2 , O 2 , and O 3 ) can form a stable Pb–O connection by directly attacking the Pb–I bonds . Anyway, in the study of the adsorption of reductive NH 3 by CH 3 NH 3 PbI 3 , it is found that the A-site CH 3 NH 3 + groups rapidly adsorb NH 3 and undergo H proton exchanges, thus blocking the interactions between the gas molecules and the skeletons; nevertheless, NH 3 can eventually break through the CH 3 NH 3 + barrier and interact with Pb to achieve stable adsorption and charge exchange.…”

“…According to Yamazoe et al, the initial move in the sensing process of semiconductor–gas molecules is to calibrate gas molecules and their active sites where the gas operates via the electronic changes introduced by gas–solid interactions. Our previous work , shows that the structural instability of the perovskite materials causes different dynamic changes around the adsorption sites. Such a property challenges the traditional static first-principles calculations; − therefore, the quantum dynamics methodology is employed to deal with such special properties. ,,− …”

“…Our previous work , shows that the structural instability of the perovskite materials causes different dynamic changes around the adsorption sites. Such a property challenges the traditional static first-principles calculations; − therefore, the quantum dynamics methodology is employed to deal with such special properties. ,,− …”

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

“…The theory plays a crucial role in investigating the several existing gas‐sensing mechanisms of semiconductor materials by applying first principle calculations [ 25–30 ] ; however, the instability of perovskite materials possibly induces the dynamic changes of adsorption patterns and active sites and reports on gas‐sensing mechanisms of organic–inorganic hybrid perovskite materials are rare. [ 31 ] Thus, it seems impossible to establish proper starting models for active sites and adsorption patterns of the gas molecules on the surface of the perovskite materials.…”

“…[ 37,38 ] In the previous work, AIMD has been reported to accurately describe the distribution characteristics of gas molecules and structural change process of adsorbing materials during adsorption over a long time‐span. [ 31,39–43 ] In addition, it is also capable of describing the detailed process from reactants, then transient state to products during the adsorption reaction at the fs time‐scale and can show detailed changes in the reaction under the effect of surrounding environments in a complex system.…”