Density functional theory studies of the structural, optoelectronic, bond stiffness and lattice dynamical properties of double perovskite oxides M2YVO6 (M= Mg, Sr): Promising candidates for optoelectronic applications

The double perovskite type oxides are deemed to be an eloquent materials to be used for applications in efficient optoelectronic devices/transducers. In order to explore physical properties of M2YVO6; (M = Mg, Sr) perovskites Full potential Linearly Augmented Plane Wave (FPLAPW) method is used in the frame work of WIEN2K code. LDA + U functional has been preferred here for getting an accurate and systematic results associated to the electronic and optical response of these compounds. These compounds fall into semiconductor category showing direct energy band gap of 1.45 eV (Mg2YVO6) and 0.82 eV (Sr2YVO6). Appearance of the energy states of different level in the conduction regions of both compounds fortify the view point that the valence electrons may jump to these states while enhancing conductivity of such devices (i.e., solar cells) whichever are fabricated for producing eternal energy. Projected density of states (PDOS) confirm the presence of Mg2+/Sr2+, Y3+, V5+, O2− in the M2YVO6 where M = Mg, Sr. In addition to it, optical analysis shows that these materials reflect very little electromagnetic radiations when fall on their surfaces. Sr2YVO6 holds relative bond stiffness greater than its standard value of ½ while it is less than half for Mg2YVO6. Phonons analysis shows few soft modes of frequency in case of Mg2YVO6 which might be due to particular orientation of monoclinic phase of the crystal structure, whereas no imaginary modes of vibrations are observed for Sr2YVO6. It looks very fabulous to claim that these compounds might be an appealing ones for optoelectronic applications due to their huge absorption rate/optical conduction ability, which also declares them very suitable materials for devising transducers. [Display omitted] •Owing to energy gap of 1.45 eV for Mg2YVO6 and 0.82 eV for Sr2YVO6, these materials are declared as semiconductor.•Diminution of energy band gap for Sr2YVO6 attributed to the weak bond strength between Sr–O as compared to Mg–O.•Relative bond stiffness for Sr2YVO6 is found greater than ½, whereas it is less than ½ for Mg2YVO6.•Insignificant amount of reflectivity with bountiful optical absorption of electromagnetic radiations has been noticed.