GaN‐based Schottky barrier ultraviolet photodetector with a 5‐pair AlGaN–GaN intermediate layer

A GaN‐based Schottky barrier diode (SBD) with a 5‐pair AlGaN–GaN intermediate layer for ultraviolet (UV) photodetector (PD) was fabricated and investigated. It was found that we could achieve a smaller dark leakage current and noise level by using the 5‐pair AlGaN–GaN intermediate layer. For our device biased at −5 V, the responsivity at 360 nm was found to be 0.26 A/W and the UV‐to‐visible rejection ratio was estimated to be 1.83 × 10 4 . At the same bias, it was found that minimum noise equivalent power and normalized detectivity of our device were 1.00 × 10 −9  W and 1.45 × 10 9  cm Hz 0.5  W −1 , respectively. This indicates a simple and effective way to fabricate high‐performance PDs for UV detection.