Fluorine Plasma Treatment for AlGaN/GaN HEMT-Based Ultraviolet Photodetector With High Responsivity and High Detectivity

AlGaN/GaN high electron mobility transistor (HEMT) has attracted great attention in ultraviolet photodetectors (UVPDs) due to the ultrahigh responsivity and high photocurrent arising from the two-dimensional electron gas (2DEG) formed in the AlGaN/GaN interface. In this letter, AlGaN/GaN HEMT-based UVPD was fabricated through fluorine plasma treatment using $\text{C}_{{4}}\text{F}_{{8}}$ gas. The dark current of the device was greatly lowered and the persistent photoconductivity (PPC) effect was effectively suppressed, leading to a high responsivity of ${1}.{3}\times {10} ^{{4}}$ A $\text{W}^{-{1}}$ and a high specific detectivity of ${1}.{8}\times {10} ^{{15}}$ Jones. The present work provides a facile and cost-effective strategy for the fabrication of high-performance AlGaN/GaN HEMT-based UVPDs.