QUASI-2D PEROVSKITE INCORPORATING PHOTOACTIVE ORGANIC CATIONS FOR OPTOELECTRONIC APPLICATIONS

Abstract

A new class of perovskites (PVSK) with general formula 𝐴2𝐶𝑛−1𝐵𝑛𝑋3𝑛−1, which has a 2D layered structure, has attracted significant attention from researchers due to the bulky organic cation (A in the formula), which can improve the stability of PVSK. Hybrid perovskites are direct-band semiconductors with a unique set of optical and electronic properties, making them promising materials for photovoltaics and optoelectronics. In addition to the optoelectronic tunability of 3D PVSKs by substitution of metal cation (B in the formula) and halide anion (X in the formula), 2D PVSKs can tune the bandgap by altering the number of Lead halide layers (n in the formula). This property makes them a promising material for solar cells and wavelength-tunable LEDs. Herein, the atomistic molecular dynamics (MD) simulation has been applied to the study of thermal properties of a novel 2D PVSK system, (𝐵𝑃𝐶𝑆𝐴+)2𝑀𝐴𝑛−1𝑃𝑏𝑛𝑋3𝑛+1. BPCSA+ is a -conjugated organic cation in the 2D PVSK, which can improve the water resistance and optical property of its PVSK. Accelrys Material Studio Forcite (version 7.0) is used to perform molecular dynamics simulations. MD allows the simulation of samples with thousands of atoms so that concentration and solvent effects can be easily pointed out. In order to gain insight into the structural and dynamic properties of 2D PVSKs, a series of MD simulations have been implemented. Under a harsh condition for solar cell operation (65 oC), the MD simulations exhibit superior thermal stability of the 2D PVSKs with BPCSA+ by non-bonding interactions.