Polarization‐Sensitive and Self‐Driven Pyro‐Phototronic Photodetectors Based on MoS<sub>2</sub>‐Water Heterojunctions
Amin Abnavi, Ribwar Ahmadi, Hamidreza Ghanbari, Mirette Fawzy, Mohammad Reza Mohammadzadeh, Fahmid Kabir, Michael M. Adachi
Abstract
Abstract Polarization‐sensitive and self‐driven pyroelectric‐based photodetectors have recently gained interest due to their potential application in artificial electronic eyes, biomedical imaging, and optical switches. Here, a photodetector based on light modulation‐induced polarization and depolarization of water molecules on the surface of a 2D MoS 2 crystal is reported. The MoS 2 ‐water heterostructure photodetector serves as a self‐driven pyro‐phototronic device that converts light‐induced thermal energy to electrical signals, leading to a transient photoresponsivity as high as 24.6 mA W −1 and a specific detectivity of 2.85 × 10 8 Jones under 470 nm wavelength at zero bias. Due to the formation of a built‐in electric field at the MoS 2 ‐water interface, this structure also has a high steady–state responsivity of 3.62 A W −1 and detectivity of 9.18 × 10 8 Jones at 3 V bias, along with a fast response time of ≈0.74 ms. Moreover, due to the rearrangement of the hydrogen bond network in the liquid water upon visible light illumination, the MoS 2 ‐water photodetector is light polarization‐sensitive. The simple fabrication process, low cost, polarization sensitivity, and high performance of the MoS 2 ‐water structure make it an excellent candidate for liquid‐compatible photodetectors.