AlGaN solar-blind ultraviolet detectors have great potential in many fields, although their performance has not fully meet the requirements until now. Here, we proposed an approach to utilize the inherent polarization effect of AlGaN to improve the detector performance. AlGaN heterostructures were designed to enhance the polarization field in the absorption layer, and a high built-in field and a high electron mobility conduction channel were formed. As a result, a high-performance solar-blind ultraviolet detector with a peak responsivity of 1.42 A/W at 10 V was achieved, being 50 times higher than that of the nonpolarization-enhanced one. Moreover, an electron reservoir structure was proposed to further improve the performance. A higher peak responsivity of 3.1 A/W at 30 V was achieved because the electron reservoir structure could modulate the electron concentration in the conduction channel. The investigation presented here provided feasible approaches to improve the performance of the AlGaN detector by taking advantage of its inherent property.

With the increasing demand for high integration and multi-color photodetection for both military and civilian applications, the research of multi-wavelength detectors has become a new research hotspot. However, current research has been mainly in visible dual- or multi-wavelength detectors, while integration of both visible light and ultraviolet (UV) dual-wavelength detectors has rarely been studied. In this work, large-scale and high-quality monolayer MoS2 was grown by the chemical vapor deposition method on transparent free-standing GaN substrate. Monolithic integration of MoS2-based visible detectors and GaN-based UV detectors was demonstrated using common semiconductor fabrication technologies such as photolithography, argon plasma etching, and metal deposition. High performance of a 280 nm and 405 nm dual-wavelength photodetector was realized. The responsivity of the UV detector reached 172.12 A/W, while that of the visible detector reached 17.5 A/W. Meanwhile, both photodetectors achieved high photocurrent gain, high external quantum efficiency, high normalized detection rate, and low noise equivalent power. Our study extends the future application of dual-wavelength detectors for image sensing and optical communication.