Gul Banat, Salman Khan Muhammad, Aasim Muhammad, Lfseisi Ahmad A, Khan Gulzar, Ahmad Hijaz
National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan.
Department of Physics, Abdul Wali Khan University, Mardan 23200, Pakistan.
ACS Omega. 2023 Aug 25;8(36):32784-32793. doi: 10.1021/acsomega.3c03756. eCollection 2023 Sep 12.
Lead-free halide perovskites are considered promising candidates as visible light absorbers with outstanding optoelectronic properties. In this work, novel kinds of lead-free halide perovskites were studied for their electronic, optical, and thermoelectric properties by employing the most precise and enhanced modified Trans-Blaha Beck-Johnson potential. The estimated band spectra of the studied materials were comparable. The materials are confirmed to have an indirect band gap semiconducting nature due to the existence of energy band gaps. Among the studied materials, CsSnI has a smaller band gap, confirming the excitation to be more energy efficient. Examining the predicted density of states and true electronic orbital contributions, we observed a progressive fluctuation along the energy axis was observed. Furthermore, the linear optical properties are calculated and studied in terms of possible optoelectronic applications. The absorption in KSnI was greater compared to the other two materials. The studied materials could be used for antireflecting coatings against UV radiation, owing to the prominent peaks in their reflectivity spectra. The Seebeck coefficient and electrical properties, as well as the positive value of all pointed to a p-type nature in these materials. From the anticipated thermoelectric properties, the materials also appear to be suitable for application in thermoelectric devices.
无铅卤化物钙钛矿被认为是具有出色光电性能的可见光吸收剂的有前途的候选材料。在这项工作中，通过采用最精确和增强的修正Trans-Blaha Beck-Johnson势，研究了新型无铅卤化物钙钛矿的电子、光学和热电性能。所研究材料的估计能带谱具有可比性。由于存在能带隙，这些材料被证实具有间接带隙半导体性质。在所研究的材料中，CsSnI的带隙较小，这证实其激发更具能量效率。通过检查预测的态密度和真实的电子轨道贡献，我们观察到沿能量轴存在渐进的波动。此外，根据可能的光电应用计算并研究了线性光学性质。与其他两种材料相比，KSnI中的吸收更大。由于其反射光谱中的突出峰值，所研究的材料可用于抗紫外线辐射的抗反射涂层。塞贝克系数和电学性质，以及所有的正值都表明这些材料具有p型性质。从预期的热电性能来看，这些材料似乎也适用于热电装置。
