Effect of Temperature on the Optoelectrical Properties of Photodetectors Based on Mo(S _X Se _{1– X} ) ₂ Alloys

Mo(S X Se 1– X ) 2 alloys, which belong to the transition metal dichalcogenides (TMDs), have attracted considerable interest due to their tunable band gap and characteristic electrical and optical properties. As a result, they can find wide applications in optoelectronics. In this paper, the photodetectors based on monolayer Mo(S X Se 1– X ) 2 alloys were fabricated and studied over a wide range of temperatures and illumination. They exhibit unprecedented performance in the wavelength range from 460 to 630 nm─high responsivity ( R = 9.08 × 10 6 A W 1– ) and specific detectivity ( D * = 9.38 × 10 13 Jones). Their properties change nonlinearly with increasing temperature. The MoS 2 and MoSe 2 -based photodetectors show the best properties at T = 300 K, while Mo(S X Se 1– X ) 2 -based photodetectors perform optimally at T = 250 K. In addition, we have proposed a design of buried electrodes intended to provide Ohmic contacts, over a wide range of ambient temperatures, with results indicating that this approach is highly promising, which has been confirmed in most of the investigated samples.