Large-Area 2D Perovskite Oxides/Organic Heterojunction Enables Highly-Sensitive Self-Powered Photodetector for Ultraviolet Light Communication

Ultraviolet (UV)-sensitive semiconductors play a key role in converting UV light into electric signals in a UV photodetector. Two-dimensional (2D) oxide perovskite, as a kind of green and stable semiconductor materials, exhibits excellent UV detection capabilities. However, the non-dense nanosheet thin film induces alternative shunts in vertical-structured devices results in high ohmic leakage currents. Large number of oxygen vacancies in 2D oxide perovskite leads to the adsorption / desorption process of oxygen molecules that slows down the device's response speed. Therefore, an inorganic-organic heterojunction that effectively fills up the pinholes in nanosheet films, effectively suppressing the dark current of the device by 100 000 times are designed. Meanwhile, the construction of inorganic-organic heterojunctions can accelerate the charge carriers' transporting process, resulting in a fast rise / decay response time of 0.7 ms / 8.5 ms. Moreover, the inorganic-organic heterojunction endows the device with excellent self-powered performance, presenting a high responsivity of 60 mA W-1. This photodetector demonstrates application potential in a UV communication system with a detection angle of 30 degrees and a close-range communication of 1.2 m. Large-area two-dimensional perovskite oxides/organic heterojunction is constructed to effectively suppressed surface pinholes, reduces the trap-assistant non-radiative recombination losses and facilitate the charge carriers' transporting process, finally achieving suppressed dark current, improve self-powered photocurrent and faster decay speed in an ultraviolet photodetector, demonstrating application prospect in a ultraviolet light communication system.image

Automated summary

An inorganic-organic heterojunction is designed to effectively fill up the pinholes in the nanosheet film, resulting in a 100,000 times suppression of the device's dark current. Moreover, the inorganic-organic heterojunction improves the transport speed of charge carriers and response time, and provides excellent self-powered performance for the device. This photodetector shows potential applications in a UV communication system.