Kiran Saira, Mumtaz Umair, Mustafa Aymen, Imran Muhammad, Hussain Fayyaz, Rasheed Umbreen, Khalil R M A, Khera Ejaz Ahmad, Nazir Alia
Institute of Physics, The Islamia University of Bahawalpur 63100 Pakistan.
Centre of Excellence in Solid State Physics, University of the Punjab Lahore Pakistan.
RSC Adv. 2023 Apr 11;13(16):11192-11200. doi: 10.1039/d3ra00078h. eCollection 2023 Apr 3.
Hybrid lead halide perovskites have been considered as promising candidates for a large variety of optoelectronic applications. By exploring novel combinations of lead-free double perovskite halides, it is possible to find a suitable replacement for poisonous lead halide perovskites, enhancing electronic and optical response for their application as optically-influenced resistive switching random access memory (RRAM). In this work, the structural, mechanical, elastic, electronic, optical, and thermoelectric characteristics of lead-free double halide perovskites were investigated by Vienna initio simulation package (VASP) to explore their role in RRAM. From the analysis of mechanical constraints, it is clear that all three composites of CsCaSnX (X = Cl, Br, I) are mechanically stable and ductile in nature. The electronic bandgap with and without spin-orbit coupling (SOC), and total and sub-total density of states (TDOS, sub-TDOS) have been calculated using the Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA) potentials. The observed direct band gaps of 3.58 eV, 3.09 eV, and 2.60 eV for CsCaSnCl, CsCaSnBr, and CsCaSnI, respectively, reveal the suitability of these specified composites as resistive switching material for RRAM devices. Additionally, the optical characteristics, such as complex refractive index, absorption coefficient, and reflectivity of the compounds under consideration have been calculated under the action of incident photons of 0 to 14 eV energy. The thermoelectric properties of CsCaSnX (X = Cl, Br, I) double perovskite halide were computed and analyzed with the help of the BoltzTraP Code.
混合卤化铅钙钛矿被认为是多种光电器件应用的有前途的候选材料。通过探索无铅双钙钛矿卤化物的新型组合，有可能找到一种合适的材料来替代有毒的卤化铅钙钛矿，增强其作为光控电阻开关随机存取存储器（RRAM）应用的电子和光学响应。在这项工作中，使用维也纳从头算模拟包（VASP）研究了无铅双卤化钙钛矿的结构、力学、弹性、电子、光学和热电特性，以探索它们在RRAM中的作用。从力学约束分析可知，CsCaSnX（X = Cl、Br、I）的所有三种复合材料在本质上都是机械稳定且具有延展性的。使用Perdew-Burke-Ernzerhof广义梯度近似（PBE-GGA）势计算了有无自旋轨道耦合（SOC）时的电子带隙以及总态密度和子总态密度（TDOS、子TDOS）。CsCaSnCl、CsCaSnBr和CsCaSnI分别观察到的直接带隙为3.58 eV、3.09 eV和2.60 eV，这表明这些特定复合材料适合作为RRAM器件的电阻开关材料。此外，在0至14 eV能量的入射光子作用下，计算了所考虑化合物的光学特性，如复折射率、吸收系数和反射率。借助BoltzTraP代码计算并分析了CsCaSnX（X = Cl、Br、I）双钙钛矿卤化物的热电性能。
