MoS₂/VO₂ Based Heterostructure Device for Highly Responsive Infrared Photodetection

Vanadium oxide (VO₂) has aroused researchers' curiosity among the transition Metal Oxides (ZnO, TiO₂, Ga₂O₃, V₂O₅, SnO₂, CuO) because of its unique semiconductor-to-metal phase transition (SMT). VO₂ is an n-type semiconductor having room temperature bandgap of 0.5-0.7 eV. It undergoes a structural transformation from semiconductor monoclinic phase (low temperature) to metallic rutile phase (high temperature) at transition temperature T_c ~ 340 K exhibiting ultra-fast, fully reversible, first-order phase transition accompanied by a notable change in electronic and optical properties. Transition Metal Dichalcogenides (TMDs) have also been considerably explored due to their distinctive electronic and mechanical properties. Nowadays, TMDs (such as MoS₂, MoSe₂ SnS₂, In₂S₃, etc) are proving to be extremely promising materials because of having tunable bandgaps depending on the number of layers of the material, high carrier mobilities, and strong exciton effects. Attributed to the outstanding properties of 2D layered materials and transition Metal Oxides, these materials are well known to give ultrafast, self-biased, and broadband photodetection. In this work, we deposited VO₂film on SiO₂substrates by using Pulsed Laser Deposition (PLD). MoS₂ film was deposited on VO₂ film using PLD form MoS₂/VO₂ heterostructure. For MoS₂/VO₂/SiO₂ device, the responsivity was found to be 0.83A/W as compared to 4.42×10^-4 A/W for VO₂/SiO₂device at 595.83 mW/cm² power density using 1550 nm laser. Clearly, the MoS₂/VO₂/SiO₂ device shows higher photodetection and hence gives better performance than VO₂/SiO₂ device.