Investigation of structural and optoelectronic properties of n-MoS2/p-Si sandwiched heterojunction photodetector

摘要

Molybdenum disulphide (MoS2), a member of the transition metal dichalcogenides family has shown excellent optoelectronic properties with direct or indirect bandgaps in visible range as well as good absorption in its 2-dimensional (2D) form. In this work, a polycrystalline MoS2 thin film is fabricated by radio frequency magnetron sputtering. X-ray diffraction (XRD) analysis of the fabricated sample reveals two hexagonal structured peaks along the (100) and (110) planes, while energy-dispersive X-ray (EDX) spectroscopy confirms a non-stoichiometric MoS2 film with a thickness of 300 nm. Raman shifts are observed at the E(2)g(1) and A(1g) phonon modes, located at 374.37 cm(-1) and 407.75 cm(-1) respectively. A sandwiched heterojunction photodetector with a SLG/n-MoS2/p-Si structure is fabricated and illuminated with violet light at 441 nm. The device exhibits significant optoelectronic properties at various laser powers at a 10 V bias voltage. The maximum value of the photocurrent is calculated as 0.79 mu A, with the responsivity as 10.4 mAW(-1) and detectivity of 6.74 x 10(9) Jones at an intensity of 0.004 mW/cm(2) . These results highlight the adaptability of the current technique that will help realize large-scale production as well as allow for the development of advanced optoelectronic devices.