In this study, a nano-flower MoSe 2 -SnS 2 humidity sensor with S defects with fast response and low humidity hysteresis was prepared for respiratory and skin humidity detection. The increase in S vacancy defects provides more adsorption sites for water molecules and also facilitates the decomposition of water molecules and improves proton conduction. The construction of MoSe 2 -SnS 2 composite prompted an increase in the specific surface area of material exposing more active sites. This promoted the adsorption of water molecules on the device surface and accelerated the electron transfer between water molecules and the sensitive layer. The nanoflower structure of MoSe 2 -SnS 2 can provide channels for water molecules to be transported into the interior of material, which can effectively shorten the response time of sensor. MoSe 2 -SnS 2 sensor exhibited faster response/recovery time (13/15 s), lower humidity hysteresis (1%) and higher stability in the range of 11%-95% RH. In addition, MoSe 2 -SnS 2 humidity sensor can successfully detect respiration and skin moisture, showing the application potential of the sensor in the detection of respiration and skin humidity. This study provides a new idea for the preparation of high-performance 2D nano humidity sensors and promotes the expansion of new application areas for the sensors.
The increasing demand for broadband and self-powered optoelectronic devices has stimulated the development of two-dimensional (2D) material-based photodetectors. Here, we construct a self-powered photodetector based on a MoSe2/SnS2van der Waals (vdW) heterostructure. The unique combination of MoSe2and SnS2provides complementary light absorption and a type-II band alignment, which generates an interfacial built-in electric field to facilitate photogenerated carrier separation and transport, enabling efficient self-powered operation without external bias. The device exhibits a broad spectral photoresponse from ultraviolet (UV) to infrared (IR) wavelengths (350–1050 nm). Under zero bias, the photodetector achieves a responsivity of 0.6 mA/W and a rapid response time of 5.8/6.1 ms (rise/fall) under 405 nm illumination, demonstrating effective self-driven photoresponse. With an applied reverse bias of −2 V, the device further reaches a responsivity of 161 mA/W and a detectivity of 8.6 × 1010Jones under 405 nm illumination. In addition, the device exhibits a low dark current of 5 pA and a high on/off ratio of 1180. These results demonstrate the potential of the MoSe2/SnS2vdW heterostructure for broadband and self-powered optoelectronic applications.
危险品化学品经营许可证（带存储）