Negahdari Fatemeh, Mokhtari Ali, Soleimanian Vishtasb
Department of Physics, Faculty of Sciences, Shahrekord University, P.O. Box 115, Shahrekord, Iran.
Nanotechnology Research Institute, Shahrekord University, Shahrekord, 8818634141, Iran.
J Mol Model. 2025 Jan 6;31(1):35. doi: 10.1007/s00894-024-06265-9.
Exploration for renewable and environmentally friendly energy sources has become a major challenge to overcome the depletion of fossil fuels and their environmental hazards. Therefore, solar cell technology, as an alternative solution, has attracted the interest of many researchers. In the present work, the CsXInBr (X = Cu or Ag) compounds as lead-free halide perovskites have been studied due to their direct energy gap in the range of solar energy, thermodynamic stability, low effective mass of electrons, and high absorption coefficient. The calculated optical gap and static refractive index about 1.35 (1.51) eV and 1.47 (1.41), respectively using BS (GW) approach for the CsAgInBr compound were in good agreement with experimental data. The threshold absorption was estimated about 1.03 (1.22) using BS (GW) approach (which correspond to the optical gap) for the CsCuInBr compound. Both compounds have small (< 0.35) reflection coefficient in the infrared, visible and UV regions and high absorption coefficient (10 cm). In the infrared and visible regions, the absorption coefficient of the Cu-based compound is much larger than the other, therefore this material can be more useful as an absorbent layer in solar cells (SC). Due to the fact that the spectrum of sunlight that reaches the earth includes 47% infrared, 46% visible and 7% ultraviolet, the Cu-based compound is more efficient for the SCs and the CsAgInBr compound is more suitable in the design of detectors.
The electronic, structural and optical properties of CsXInBr (X = Cu or Ag) compounds have been calculated and analyzed using the Abinit computational package based on density functional theory (DFT). The ultrasoft pseudopotentials within the framework of the generalized gradient approximation (GGA) are adopted for the electron exchange-correlation potential and are employed for the calculations of the electronic, and optical properties as well. The wave functions have expanded on a plane-wave basis set to cutoff energy of 950 eV and 64 k-points with a k-mesh of 4 × 4 × 4 are considered for the integrations over the Brillouin zone. The behavior of the real and imaginary parts of the dielectric function and other optical quantities have been simulated using both RPA-GW (random phase approximation with GW energies) and Bethe-Salpeter formalisms.
探索可再生且环保的能源已成为克服化石燃料枯竭及其环境危害的一项重大挑战。因此，太阳能电池技术作为一种替代解决方案，已引起众多研究人员的关注。在当前工作中，CsXInBr（X = Cu或Ag）化合物作为无铅卤化物钙钛矿受到了研究，这是由于它们在太阳能范围内具有直接能隙、热力学稳定性、低电子有效质量以及高吸收系数。使用BS（GW）方法计算得到的CsAgInBr化合物的光学能隙和静态折射率分别约为1.35（1.51）eV和1.47（1.41），与实验数据吻合良好。使用BS（GW）方法（对应于光学能隙）计算得到的CsCuInBr化合物的阈值吸收约为1.03（1.22）。两种化合物在红外、可见光和紫外区域的反射系数都很小（< 0.35）且吸收系数高（10 cm）。在红外和可见光区域，铜基化合物的吸收系数比另一种大得多，因此这种材料作为太阳能电池（SC）的吸收层可能更有用。由于到达地球的太阳光光谱包括47%的红外光、46%的可见光和7%的紫外光，铜基化合物对太阳能电池更有效，而CsAgInBr化合物在探测器设计中更合适。
使用基于密度泛函理论（DFT）的Abinit计算软件包对CsXInBr（X = Cu或Ag）化合物的电子、结构和光学性质进行了计算和分析。电子交换关联势采用广义梯度近似（GGA）框架内的超软赝势，并用于电子和光学性质的计算。波函数在平面波基组上展开，截止能量为950 eV，在布里渊区积分时考虑4×4×4的k网格和64个k点。使用RPA - GW（带GW能量的随机相位近似）和贝叶斯 - 萨尔皮特形式体系对介电函数的实部和虚部以及其他光学量的行为进行了模拟。
