Enhance the responsivity of self-driven ultraviolet photodetector by (Al,Ga)N nanowire/graphene/PVDF heterojunction with high stability.

Abstract

Due to the low-power consumption, self-driven ultraviolet (UV) photodetectors have great potentials in a broad range of applications, such as optical communication, ozone monitoring, bio-medicine, and flame detection. In this Letter, it is pretty novel to enhance the photocurrent and responsivity of self-driven UV photodetectors by (Al,Ga)N nanowire/graphene/polyvinylidene fluoride (PVDF) heterojunction successfully. Compared to those of the photodetector with only nanowire/graphene heterojunction, it is found that both the photocurrent and responsivity of the photodetector with nanowire/graphene/PVDF heterojunction can be enhanced more than 100%. It is proposed that PVDF could maintain the internal gain by increasing the number of carrier cycles. Furthermore, this photodetector can also have a high detectivity of 5.3×1011 Jones and fast response speed under 310 nm illumination. After preserving for one month without any special protection, both photocurrent and responsivity of the photodetector with nanowire/graphene/PVDF heterojunction are demonstrated to be quite stable. Therefore, this work paves an effective way to improve the performance of photodetectors for their applications in the fields of next-generation optoelectronic devices.