Lead (Pb) free non-toxic perovskite solar cells have become more important in the commercialization of the photovoltaic devices. In this study the structural, electronic, optical and mechanical properties of Pb-free inorganic metal halide cubic perovskites CsBX3 (B = Sn, Ge; X = I, Br, Cl) for perovskite solar cells are simulated using first-principles Density Functional Theory (DFT). These compounds are semiconductors with direct band gap energy and mechanically stable. Results suggest that the materials have high absorption coefficient, low reflectivity and high optical conductivity with potential application in solar cells and other optoelectronic energy devices. On the basis of the optical properties, one can expect that the Germanium (Ge) would be a better replacement of Pb as Ge containing compounds have higher optical absorption and optical conductivity than that of Pb containing compounds. A combinational analysis of the electronic, optical and mechanical properties of the compounds suggests that CsGeI3 based perovskite is the best Pb-free inorganic metal halide semiconductor for the solar cell application. However, the compound with solid solution of CsGe(I0.7Br0.3)3 is found to be mechanically more ductile than CsGeI3. This study will also guide to obtain Pb-free organic perovskites for optoelectronic devices.
展开▼
机译:无铅(Pb)无毒钙钛矿太阳能电池在光伏器件的商业化中变得越来越重要。在这项研究中,使用第一原理密度泛函理论模拟了无铅无机金属卤化物立方钙钛矿CsBX3(B = Sn,Ge; X = I,Br,Cl)的结构,电子,光学和机械性能(DFT)。这些化合物是具有直接带隙能且机械稳定的半导体。结果表明该材料具有高吸收系数,低反射率和高光导率,具有潜在的应用前景,可用于太阳能电池和其他光电能量器件。基于光学性质,可以预期锗(Ge)将更好地替代Pb,因为含Ge的化合物比含Pb的化合物具有更高的光吸收和光导率。化合物的电子,光学和机械性能的综合分析表明,基于CsGeI3的钙钛矿是太阳能电池应用中最好的无铅无机金属卤化物半导体。但是,发现具有CsGe(I0.7Br0.3)3固溶体的化合物在机械上比CsGeI3更具延展性。该研究还将指导获得用于光电器件的无铅有机钙钛矿。
展开▼