Enhanced photoresponsivity of the MoS2-GaN heterojunction diode via the piezo-phototronic effect

Combining layered MoS2 flakes with conventional 3D semiconductors is a feasible route to fabricate high-quality heterojunction devices by harnessing the advantages of both materials. Here, we present a pressure-modulated heterojunction photodiode that is composed of an n-type multilayer MoS2 and a p-type GaN film via the piezo-phototronic effect. Under the illumination of 365 nm incident light, a strong photoresponse is observed with response and recovery times of ~66 and 74 ms, respectively. Under a pressure of 258 MPa, the photoresponsivity of this photodiode can be tuned by the piezo-phototronic effect arising from the GaN film to ~3.5 times. Because of the lowered junction barrier with an applied external pressure (strain), more photogenerated carriers can successfully pass through the junction area without recombination, which results in an enhancement effect. This work provides a possible path for the implementation of high-performance electronic and optoelectronic devices that are based on hybrid heterostructures via human interfacing. A device that combines the advantages of both conventional and modern atom-thick semiconductors has been created. Two-dimensional materials have a wide range of exotic electronic properties that could lead to new generation of electronic devices. However, achieving the broadest diversity of functionality will probably necessitate combing these flat materials with conventional semiconductors. Zhong Lin Wang from the Beijing Institute of Nanoenergy and Nanosystems and colleagues created a photodetector whose response can be tuned by applying pressure. They stacked two-dimensional molybdenum disulfide onto a thin film of gallium nitride to create a diode that generates an electrical signal on exposure to light with a wavelength of 365 nanometers. The team showed that the photoresponsivity could be boosted by a factor of 3.5 when an external pressure was applied. Here, we present a pressure-modulated heterojunction photodiode composed of n-type multilayer MoS2 and p-type GaN film by piezo-phototronic effect. Under the illumination of 365 nm incident light, strong photo-response is observed with a response time and recovery time of ~66 and 74 ms, respectively. Upon the pressure of 258 MPa, the photoresponsivity of this photodiode can be enhanced for about 3.5 times by piezo-phototronic effect arising from the GaN film. Due to the lowered junction barrier upon applying an external pressure (strain), more photo-generated carriers can successfully pass through the junction area without recombination, resulting in the enhancement effect.