RESUMEN
The vacancy-ordered double perovskite Cs2PdBr6 has the advantages of good optoelectronic properties, environmental friendliness, and high stability. It has been experimentally confirmed by researchers as an optoelectronic material with broad application prospects and research value, and is regarded as a potential substitute for lead halide perovskites. In this paper, based on the first-principles calculations in the framework of density functional theory, the crystal structure, elastic, electronic, and optical properties of Cs2PdBr6 under hydrostatic pressure of 0-6 GPa have been investigated with a step size of 0.5 GPa. The calculated results obtained under the condition of 0 GPa hydrostatic pressure are in good agreement with the existing experimental values. When the hydrostatic pressure is applied, the crystal structure parameters of Cs2PdBr6 appear nonlinear changes, but it can still maintain a stable cubic crystal structure. With the increase of pressure, the bulk modulus, shear modulus, and Young's modulus of Cs2PdBr6 increase gradually, and its ductility also improves gradually. Hydrostatic pressure can reduce the bandgap value of Cs2PdBr6, thereby enhancing the optoelectronic properties such as absorption and conductivity. In summary, hydrostatic pressure can change the bandgap value of Cs2PdBr6, improve its optoelectronic performance, and make it more suitable for use as the light-absorbing layer in solar cells.
RESUMEN
The mechanical, electronic structure and optical properties of aluminium based double halide perovskite were calculated by density functional theory. The formation energy and elastic constant confirm the stability of the cubic perovskite materials. The materials are all ductile and suitable for flexible photovoltaic and optoelectronic devices. The band gap values vary from 0.773 eV to 3.430 eV, exactly corresponding to the range of ideal band gap values for good photoresponse. The band structure analysis shows that all the materials possess small effective mass, which indicates a good transport of carriers. And these materials have a broad energy range of optical absorption for utilization and a detector of photons. Moreover, less expensive K2AgAlBr6 were investigated for comparison with materials containing a cesium element, and according to the results, is also a candidate for photoelectronic devices due to the similar properties.