Realization of a Piezophototronic Device Based on Reduced Graphene Oxide/MoS2 Heterostructure

In this letter, we present a piezophototronic device based on reduced graphene oxide (rGO)/MoS2 heterostructure on a flexible substrate. Here, we benefit from the semiconducting and piezoelectric behaviors of MoS2 sheets, besides the 2-D properties of rGO sheets. To elaborate the piezophototronic behavior, first, we have studied the stress-induced and optoelectronic behaviors separately. It is shown that the rGO sheets play a dominant role in stress-induced variations of the electrical behavior of rGO/MoS2-based device. On the other hand, utilizing MoS2 sheets results in increasing the photoresponsivity of rGO/MoS2-based photodetector by a factor of about 2.1, comparing with rGO-based device (at lambda = 450 nm). Finally, the investigated piezophototronic behavior of the realized rGO/MoS2-based device proves a responsivity enhancement of similar to 97%, by applying illumination and alternative strain (0.03%) simultaneously. The observed responsivity enhancement is attributed to the stress-induced piezopotential in MoS2 sheets, and the modulation of the Schottky barrier at rGO/MoS2 interface. The achieved results open up promising horizons for the coupling superior properties of MoS2 sheets, to realize new generation of high performance optoelectronic devices.