Highly Wavelength‐Selective Self‐Powered Solar‐Blind Ultraviolet Photodetector Based on Colloidal Aluminum Nitride Quantum Dots

Abstract Colloidal quantum dots are semiconductor nanocrystals endowed with unique optoelectronic properties. A major challenge to the field is the lack of methods for synthesizing quantum dots exhibit strong photo‐response in the deep‐ultraviolet (DUV) band. Here, a facile solution‐processed method is presented for synthesizing ultrawide bandgap aluminium nitride quantum dots (AlN QDs) showing distinguished UV‐B photoluminescence. Combined with the strong optical response in solar blind band, a solution‐processed, self‐powered AlN‐QDs/β‐Ga₂O₃ solar‐blind photodetector is demonstrated. The photodetector is characterized with a high responsivity of 1.6 mA W⁻¹ under 0 V bias and specific detectivity 7.60 × 10⁻¹¹ Jones under 5 V bias voltage with good solar blind selectivity. Given the solution‐processed capability of the devices and extraordinary properties of AlN QDs, this study anticipates the utilization of AlN QDs will open up unique opportunities for cost‐effective industrial production of high‐performance DUV optoelectronics for large‐scale applications.