Ultraviolet Photodetector Based on Mg–N: Β‐Ga 2 O 3 /GaN Heterostructure

Ultra‐wide bandgap Ga 2 O 3 semiconductor is regarded as an ideal candidate material for next‐generation Ultraviolet photodetectors (UV PDs). However, the presence of intrinsic defects, particularly oxygen vacancies (Vo), in Ga 2 O 3 films impedes the enhancement of photoelectric performance. Herein, an Mg–N co‐doped β‐Ga 2 O 3 film has been successfully grown on a p‐GaN substrate via a simple one‐step thermal oxidation method, which effectively suppresses Vo concentrations and reduces the dark current density of Ga 2 O 3 /GaN heterojunction devices to 1.67 × 10 −11 A/cm 2 , thereby significantly improving the device performance. The fabricated Mg–N: β‐Ga 2 O 3 /GaN heterojunction PDs achieve a responsivity of 0.25 A/W under UV illumination, with a response time of 3.1 ms (rise)/5.1 ms (decay) at −2 V. Meanwhile, the responsivity and response time are 0.19 mA/W and 1.87 ms (rise)/1.2 ms (decay) at 0 V, respectively, indicating relatively high self‐powered performance. The noise mechanism of the device is predominantly governed by 1/ f noise, and the detectivity is calculated to be 1.6 × 10 13 Jones. Benefiting from high detection performance, the device exhibits excellent imaging capability, highlighting its application potential in next‐generation UV PDs.