Feasibility study of MoS2 based junctions for infrared detection

Abstract

The tunable material characteristics of molybdenum disulfide (MoS₂) for next-generation of IR detectors have gained a lot of attention in recent years. Post-deposition morphological and microstructural characterizations of MoS₂ films were carried out by FESEM, AFM, XRD and Raman techniques. A homogeneous distribution of grains was observed from the FESEM micrographs. In this work, the photoresponse of MoS₂ based junctions has been studied elaborately using the current-voltage and current-time measurements. The near IR response was evaluated from the current On/Off ratio, rise time, fall time, responsivity and specific detectivity of the detectors upon illumination of IR source of wavelength 850 nm, 940 nm, and 1060 nm. MoS₂ based resistive conductor, n-MoS₂/p-Si intrinsic heterojunction, n-MoS₂/p-MoS₂ homojunction, and Pt/MoS₂ Schottky junction structures were fabricated to study the IR response. Pt/MoS₂ Schottky junction has shown the highest current On/Off ratio, responsivity, and specific detectivity, whereas MoS₂ based photoconductors have exhibited fastest IR response.