Construction of n-SnO2 microwire/p-InGaN heterojunction for self-powered and broadband photodetector

The self-biased photodetectors without an external power source, which have been extensively utilized in wireless communication, imaging, light-sensing and so on, are urgently in demand. In this study, we successfully constructed a self-energized photodetector on the basis of n-SnO2 microwire/p-InGaN heterojunction, which exhibits an good current rectification property in darkness and superior photovoltaic behaviors upon ultraviolet–visible (330–530 nm) light irradiation. Under 360 nm light irradiation, the designed photodetector reveals a superior photoresponsivity surpassing 152.5 mA/W, a high detectivity exceeding 3.77 × 1012 Jones, a fast response speed (the rising/decaying times ∼0.2/14.6 ms) and a high Ion/Ioff ratio over 105 when operated in a self-driven manner. Additionally, the responsivities of our self-powered photodetector were derived to about ∼85.2 and 5.5 mA/W upon illumination with visible light of 405 and 532 nm, respectively. The highly-sensitive broad-spectrum photodetection mechanism of the as-constructed n-SnO2 microwire/p-InGaN heterojunction is resulted from the combination of ultraviolet-sensitive SnO2 monocrystals and visible-sensitive capability of InGaN material. The resultant photoresponse properties of the designed n-SnO2 microwire/p-InGaN heterojunction photodetector that having merits of low cost and facile construction, can enable a competitive and potential candidate with prospect of developing high-performance self-biased photodetectors in the broadband ranging from ultraviolet to visible.