Influence of halide composition on the structural, electronic, and optical properties of mixed CH\(_3\)NH\(_3\)Pb(I\(_{1-x}\)Br\(_x\))\(_3\) perovskites calculated using the virtual crystal approximation method

We investigate the structural, electronic and optical properties of mixed bromide-iodide lead perovskite solar cell CH\(_3\)NH\(_3\)Pb(I\(_{1-x}\)Br\(_x\))\(_3\) by means of the virtual crystal approximation (VCA) within density functional theory (DFT). Optimizing the atomic positions and lattice pa...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2017-09
Main Authors: Un-Gi Jong, Chol-Jun Yu, Nam-Hyok Kim, Guk-Chol Ri
Format: Article
Language:English
Subjects:
Absorptivity
Approximation
Carrier mobility
Crystal structure
Current carriers
Density functional theory
Electromagnetic absorption
Energy gap
Excitons
Lattice parameters
Mathematical analysis
Optical properties
Perovskites
Photon absorption
Photovoltaic cells
Quadratic equations
Solar cells
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We investigate the structural, electronic and optical properties of mixed bromide-iodide lead perovskite solar cell CH\(_3\)NH\(_3\)Pb(I\(_{1-x}\)Br\(_x\))\(_3\) by means of the virtual crystal approximation (VCA) within density functional theory (DFT). Optimizing the atomic positions and lattice parameters increasing the bromide content \(x\) from 0.0 to 1.0, we fit the calculated lattice parameter and energy band gap to the linear and quadratic function of Br content, respectively, which are in good agreement with the experiment, respecting the Vegard's law. With the calculated exciton binding energy and light absorption coefficient, we make sure that VCA gives consistent results with the experiment, and the mixed halide perovskites are suitable for generating the charge carriers by light absorption and conducting the carriers easily due to their strong photon absorption coefficient, low exciton bindign energy, and high carrier mobility at low Br contents. Furthermore analyzing the bonding lengths between Pb and X (I\(_{1-x}\)Br\(_x\): virtual atom) as well as C and N, we stress that the stability of perovskite solar cell is definitely improved at \(x\)=0.2.
ISSN:2331-8422
DOI:10.48550/arxiv.1604.08497