Ultrasensitive p-n junction UV-C photodetector based on p-Si/β-Ga2O3 nanowire arrays

Ultrasensitive UV-C photodetector (PD) based on beta-Ga2O3 nanowires (NWs) were fabricated on p-type Si substrate using glancing angle deposition technique inside RF/DC sputtering chamber. The formation of well-aligned NWs with an average length of similar to 270 nm was confirmed with the help of field emission scanning electron microscope (FE-SEM) images. Also, the fabricated beta-Ga(2)O(3 )NWs array were polycrystalline in nature. Furthermore, a good photo absorption and photoemission were obtained from the fabricated sample. The PD fabricated using beta-Ga2O3 NW operated in the UV-C region (275 nm) with a recorded responsivity of 31.71 A/W, detectivity of 1.37 x 10(12) Jones and an NEP of 2.44 x 10(-12) W at + 5 V. Additionally, the PD was able to respond at a very low power light of 6.37 mu W/cm(2). The transient response of the fabricated device shows a rise time and fall time of 0.18 s and 0.25 s respectively. The high performance was attributed to the strong p-n junction which could separate the photogenerated carriers efficiently.

Automated summary

A highly sensitive UV-C photodetector based on beta-Ga2O3 nanowires was fabricated, showing good photo absorption and emission properties. It operated efficiently in the UV-C region with high responsivity, detectivity, and low noise equivalent power. The device also demonstrated fast transient response times due to the strong p-n junction.