Quantum confinement effect on the electronic and optical properties of two-dimensional halide perovskites

Abstract

Two-dimensional (2D) halide perovskites have garnered significant attention due to their inherent stability, excellent optoelectronic properties, and versatile structural diversity, making them promising for solar cell applications. Here, by using the first-principles calculation based on density functional theory, the structural and optoelectronic properties of 2D halide perovskites are investigated. Results reveal a clear relationship in structural and optoelectronic properties. The band gaps of 2D halide perovskites decrease with the sheet of inorganic (or organic) layers increasing (or decreasing). Calculated charge density at the band edges and averaged electrostatic potential explain this structure-properties relationship comes from quantum confinement effect induced by the unique quantum-well-like structure. This theoretical work provides comprehensive understanding of the optoelectronic properties and a guideline for designing new 2D halide perovskite with desired optoelectronic properties.