Bulk photovoltaic effect of ferroelectric Sc-doped GaN thin films toward self-powered light detection

Gallium nitride (GaN), one of the most popular optoelectronic materials in the semiconductor industry, has gained renewed interest as a ferroelectric material when alloyed with scandium. However, the inherent bulk photovoltaic effect (BPE) of GaN-based ferroelectrics has yet to be fully exploited. In this work, a BPE-driven self-powered photodetector based on ferroelectric Sc-doped GaN thin film was fabricated without the usage of a p-n contact. At zero bias, this device features a high responsivity of 45.9 mA/W, a high detectivity of 2.27 × 1011 Jones, a fast response speed of sub-ms-level, a high UV selectivity of 91.3, and an imaging capacity. This work demonstrates the potential of GaN-based ferroelectric thin films in energy-efficient optoelectronic devices.