Metal–semiconductor–metal structured photodetectors based on β-Ga2O3 thin films were fabricated. Because of the high dark-resistance and considerable photoconduction, extremely uneven distribution of electric field is formed in the device under solar-blind UV light-illumination when a bias is added. Avalanche multiplication takes place in the high-field area near the electrode edges. Responsivity up to 46 A/W and the corresponding external quantum efficiency of 23 000% are observed. The photodetector shows a peak response at 248 nm, a sharp cut off edge at 262 nm (at −20 dB), and a fast response speed with a fall time of about 26.7 μs. Because of the ultralow response out of band, the rejection ratio R 254/365nm is larger than 7 orders of magnitude, where the illumination intensity at 254 and 365 nm are 0.5 and 1.2 mW/cm2, respectively.

The sensitivity to weak light signal is a key parameter for UV photodetectors. However, highly sensitive device has to suffer slow response speed (with photoconductive gain) or large noise current...

Filter‐free color imaging is the long‐pursued solution for its simple structure, low cost, and high stability. However, a spectroscopic unit is still necessary for the current Si‐based imaging unit due to the intrinsic photoresponse properties of Si. Here, the authors demonstrate a filter‐free color‐resolved single‐pixel imaging (SPI) by combining the working mechanism of computational ghost imaging and the response characteristic of perovskite. Benefitting from a broad linear dynamic range (106.5 dB) and a high detectivity (4.03 × 1014 Jones) of the fabricated ultrasensitive MAPbBr3 microwire arrays (MWAs) photodetector, the light attenuation caused by an object can be effectively correlated with its color. The reconstructed images of both transmissive and reflective color objects show a high wavelength resolution reaching 20 nm in the range of 400–540 nm, which is impossible to achieve by commercial silicon‐photodiode‐based ones. This work can open a new door for the image acquisition of color‐sensitive objects and also pave a way for the evolution of the next generation of detectors and cameras with low‐dimensional perovskite materials.