Tarekuzzaman Md, Ishraq Md Hasin, Shahadath Nazmul, Kabir Md Raihan, Rayhan M A, Ahmad Sohail, Qader Md Abdul, Rasheduzzaman Md, Arafat Yasir, Hasan Md Zahid
Materials Research and Simulation Lab, Department of Electrical and Electronic Engineering, International Islamic University Chittagong, Kumira, Chittagong, 4318, Bangladesh.
Department of Electrical and Electronic Engineering, International Islamic University Chittagong, Kumira, Chittagong, 4318, Bangladesh.
Sci Rep. 2025 Jul 13;15(1):25304. doi: 10.1038/s41598-025-91458-2.
This paper presents a comprehensive investigation of the structural, electronic, mechanical, optical, and thermodynamic properties of LiXI (X = Ca, Sr, Ba) alkali-based single halide perovskites using DFT-based first-principles calculations for the first time. This cubic perovskite structure, LiXI (X = Ca, Sr, Ba), exhibits positive phonon dispersion curves, confirming these compounds' dynamical stability. Analysis of the electronic band structure and density of states reveals that LiXI (X = Ca, Sr, Ba) are indirect band gap semiconductors with band gap values determined using GGA (HSE06) are 2.363 (3.475) eV, 2.363 (3.623) eV & 2.350 (3.698) eV for LiCaI, LiSrI, and LiBaI, respectively. The optical properties of LiXI compounds (X = Ca, Sr, Ba) were analyzed, focusing on the dielectric function, absorption coefficient, conductivity, reflectivity, refractive index, and loss function. The study revealed a broad absorption spectrum, high dielectric function, and refractive index at low energy states, along with high conductivity and low loss function and reflectivity, highlighting their potential for use in electronic and optoelectronic devices. The elastic constants were assessed to fulfill stability criteria, confirming the solids mechanical stability and ductility. The Zener anisotropy index (A) and equivalent anisotropy (A) were calculated, and three-dimensional diagrams of elastic moduli were generated using the ELATE tool, indicating that our studied compounds display anisotropic behavior. Additionally, the low thermal conductivity and Debye temperature suggest that LiXI (X = Ca, Sr, Ba) are suitable for thermal barrier coating material. Overall, these alkali-based halide perovskites exhibit promising applications in optoelectronics and semiconductors.
本文首次使用基于密度泛函理论（DFT）的第一性原理计算，对LiXI（X = Ca、Sr、Ba）碱基金属单卤化物钙钛矿的结构、电子、力学、光学和热力学性质进行了全面研究。这种立方钙钛矿结构LiXI（X = Ca、Sr、Ba）呈现出正的声子色散曲线，证实了这些化合物的动力学稳定性。对电子能带结构和态密度的分析表明，LiXI（X = Ca、Sr、Ba）是间接带隙半导体，使用广义梯度近似（GGA）（HSE06）确定的带隙值，LiCaI、LiSrI和LiBaI分别为2.363（3.475）eV、2.363（3.623）eV和2.350（3.698）eV。分析了LiXI化合物（X = Ca、Sr、Ba）的光学性质，重点关注介电函数、吸收系数、电导率、反射率、折射率和损耗函数。研究发现，在低能态下具有宽吸收光谱、高介电函数和折射率，以及高电导率、低损耗函数和反射率，突出了它们在电子和光电器件中的应用潜力。评估弹性常数以满足稳定性标准，证实了固体的力学稳定性和延展性。计算了齐纳各向异性指数（A）和等效各向异性（A），并使用ELATE工具生成了弹性模量的三维图，表明我们研究的化合物表现出各向异性行为。此外，低热导率和德拜温度表明LiXI（X = Ca、Sr、Ba）适用于热障涂层材料。总体而言，这些碱基金属卤化物钙钛矿在光电子学和半导体领域展现出了广阔的应用前景。
