Related Experiment Video
Updated: Jun 15, 2025
Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films
Published on: September 8, 2017
First principles study on the structural stability, mechanical stability and optoelectronic properties of
Kefyalew Wagari Guji1, Tesfaye Abebe Geleta2, Nabil Bouri3
1Physics Department, Bule Hora University P. O. BOX 144, Bule Hora Ethiopia gujikefyalew@gmail.com.
Abstract:
Metal-halide perovskites are recognized as cutting-edge solar energy technology, boasting remarkable absorption capabilities, minimal environmental impact, and cost-effectiveness. This study delves into the structural stability, mechanical stability, and optoelectronic properties of lead-free halide perovskites, specifically XMgI3 (X = Li/Na), by utilizing the CASTEP and WIEN2k software along with the GGA-PBE and Tran-Blaha modified Becke-Johnson (TB-mBJ) exchange-correlation functions to compare their electronic properties. The structural and mechanical stabilities were confirmed by assessing their tolerance factor and formation energy and by evaluating their elastic constants, respectively. Using the TB-mBJ exchange-correlation potential function, the calculated indirect band gap values for LiMgI3 and NaMgI3 were 2.474 and 2.556 eV, respectively. These band gaps are suitable for solar energy harvesting due to their broad optical absorption ranging from infrared to visible light. The partial density of states and the total density of states were determined to investigate the contribution of individual atoms. Consequently, this study can guide researchers focusing on the experimental synthesis of these materials at the laboratory scale for in-depth exploration, particularly in applications such as photovoltaics and various optoelectronic devices.
Related Concept Videos
02:30Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
01:59Relative Stabilities of Alkenes