WS<sub>2</sub>/WO<sub>3</sub> Heterostructure-Based Photodetectors on SiO<sub>2</sub>/Si for Future Optoelectronics
P.V. Karthik Yadav, Y. Ashok Kumar Reddy
Abstract
Photodetectors are becoming indispensable components in next-generation optoelectronic devices and photonic integrated circuits. Emerging materials like transition metal dichalcogenides (TMDs) are suitable for broad-band photodetectors owing to their significant properties like high carrier mobility, bandgap tunability, flexibility, and integration. Herein, we report a strategic development of WS 2 /WO 3 heterostructures by sputtering and chemical vapor deposition techniques to fabricate a metal–semiconductor–metal planar-structured Ag/WS 2 /WO 3 /Ag photodetector device with interdigitated Ag electrodes. A comparative study has been made based on the photodetector performance between the WS 2 /WO 3 heterostructure and pristine WO 3 and WS 2 thin-film-based devices. The WS 2 /WO 3 heterostructure shows a responsivity of 2.94 and 2.02 A/W under a UV intensity of 0.66 mW/cm 2 and a visible intensity of 0.58 mW/cm 2 illuminations, respectively. In this heterostructure, the WS 2 layer helps in trapping the photo-excited charge carriers from WO 3 and also reduces the recombination losses by absorbing the emitted radiation with WO 3 . The simple interdigitated electrodes allowed the WS 2 /WO 3 test device to achieve a quick response and recovery time of 100 ms. A similar approach can be realized to fabricate the other TMD-based hybrid heterostructures for enhanced performance of real-life broad-band photodetector applications.