High responsivity and stability of MSM structured MoS2 photodetectors by remote hydrogen plasma treatment and alternating growth of Al2O3/HfO2 passivation layers

Abstract

Molybdenum disulfide (MoS₂) is a representative material of transition metal dichalcogenides with a wide range of potential practical applications. However, the low responsivity and relatively short lifespan of MoS₂ photodetectors restrict their further development. To enhance the performance of MoS₂ photodetectors, we propose a strategy involving defect introduction and surface passivation. Sulphur vacancy defects are introduced in MoS₂ through remote hydrogen plasma treatment and surface passivation of MoS₂ is achieved by alternating growth of Al₂O₃/HfO₂ passivation layers. The obtained MoS₂ photodetector features a high responsivity of 567 A W⁻¹, a specific detectivity of 1.12 × 10¹⁰ jones, and a response time of 10.51/15.78 s at a bias of −5 V. Moreover, the obtained MoS₂ photodetector maintains excellent stability. It is demonstrated that, after 2 months of placement in an atmospheric environment, the responsivity and the specific detectivity are maintained at approximately 95% of the fresh device, while the response time slightly increases. Finally, the underlying physical mechanism based on the energy band diagram has been proposed to interpret the obtained experimental results. The simple and efficient method proposed in this study for improving the performance of the MoS₂ photodetector can open up new avenues for research in MoS₂-based photoelectric devices.