Laser-induced photoresistance effect in Si-based vertical standing MoS2 nanoplates heterojunction for self-powered high-performance broadband photodetector
MoS2 has attracted extensive attention as the basic configuration of optoelectronic systems because of its outstanding optical and electronic properties. Although high performance MoS2-based photodetectors have been realized by many groups, these studies are still in their initial stages of research, and more importantly the usual photocurrent or photovoltage signals are fundamentally susceptible, thus seeking for novel structure or working principle devices becomes more fascinating. Here, the MoS2/Si heterojunction is prepared with vertically oriented nanoplate structure and we exploit it as a photovoltage, photocurrent and photoresistance-based multifunctional self-powered position sensitive detector (PSD). The PSD exhibits unprecedented performances with very high sensitivity (391.1 mV/mm, 285.2 μA/mm, and 21.61 KΩ/mm for photovoltage, photocurrent and photoresistance responses respectively), excellent linearity (nonlinearity < 2%), and very fast response speed (4.75 ms/6.33 ms), all of which are much better than these obtained in many other systems. More importantly, it is the first time that the lateral photoresistance (LPRE) is observed in the MoS2/Si heterojunction. Based on the theoretical analysis of the scattering or transportation modulation of photo-generated carriers on the drifted carriers in the MoS2/Si heterojunction, these results were well explained.