Hasan Md Mehedi, Sarker Md Amran, Islam Md Rafiqul, Islam Md Rasidul
Department of Materials Science and Engineering, Khulna University of Engineering & Technology (KUET), Khulna 9203, Bangladesh.
Department of Electrical and Electronic Engineering, Khulna University of Engineering & Technology (KUET), Khulna 9203, Bangladesh.
ACS Omega. 2024 Aug 10;9(33):35301-35312. doi: 10.1021/acsomega.4c00209. eCollection 2024 Aug 20.
To commercialize optoelectronic products and perovskite-based solar cells, nontoxic inorganic cubic metal halide perovskites have gained popularity. This study presents the structural, mechanical, electronic, and optical properties of novel lead-free metal cubic halide perovskites AlGeX (X = F, Cl, Br, and I) using the first-principles Density Functional Theory (DFT) approach. The verification of the mechanical stability of all compounds is conducted through Born stability criteria and formation energy. All of the compounds in the elastic investigations exhibit anisotropy, ductility, and elastic stability. The electronic band structures estimated by HSE06 and GGA-PBE functional demonstrate indirect to direct band gap transformation after substituting the halide F with the halides Cl, Br, and I. The tunability of halide-dependent energy bandgaps and the underestimation of energy band gaps are also noticed for the studied compounds by comparing the results obtained from the GGA-PBE functional and HSE06 investigations. The origins of bandgap transformation as well as halide-dependent energy gap modulation are explained by both the partial and total density of states (PDOS and TDOS). The results presented here suggest that all the compounds show low reflectivity, a high absorption coefficient, and also high optical conductivity in the visible and UV regions, making these materials suitable for multijunctional solar cells. Also, these materials have a greater impact on other optoelectronic device applications. Compared to other compounds, the optical investigation reported here demonstrates that AlGeI exhibits excellent optical conductivity and absorption in the visible region.
为了使光电子产品和钙钛矿基太阳能电池商业化，无毒无机立方金属卤化物钙钛矿受到了广泛关注。本研究采用第一性原理密度泛函理论（DFT）方法，展示了新型无铅金属立方卤化物钙钛矿AlGeX（X = F、Cl、Br和I）的结构、力学、电子和光学性质。通过玻恩稳定性判据和形成能对所有化合物的力学稳定性进行了验证。弹性研究中的所有化合物均表现出各向异性、延展性和弹性稳定性。由HSE06和GGA-PBE泛函估计的电子能带结构表明，在用Cl、Br和I取代卤化物F后，发生了从间接带隙到直接带隙的转变。通过比较GGA-PBE泛函和HSE06研究得到的结果，还注意到了所研究化合物中卤化物依赖的能带隙可调性以及能带隙的低估现象。通过部分和总态密度（PDOS和TDOS）解释了带隙转变以及卤化物依赖的能隙调制的起源。此处给出的结果表明，所有化合物在可见光和紫外区域均表现出低反射率、高吸收系数和高光学电导率，这使得这些材料适用于多结太阳能电池。此外，这些材料对其他光电器件应用也有较大影响。与其他化合物相比，此处报道的光学研究表明，AlGeI在可见光区域表现出优异的光学电导率和吸收性能。
