Low-Temperature Operation of Gallium Nitride Based Ultraviolet Photodetectors

摘要

Developing sensors for space-based applications is complicated by the harsh environment which they must reliably operate in, such as extreme temperatures and high levels of radiation. Sensors capable of withstanding the extreme cold of deep space without external heating have the ability to greatly reduce spacecraft weight and therefore cost. Ultraviolet (UV) gallium nitride (GaN)-based metal-semiconductor-metal photodetectors have been fabricated and characterized under dark and UV illuminated (365 nm) conditions from room temperature down to -98.0°C. Photodetector sensitivities in the form of photocurrent-to-dark-current ratio (PDCR) and responsivity (R) showed small changes with decreasing temperature (PDCR = 0.18, 0.21 and R = 505 AAV, 468 AAV at 23.3°C and -98.0°C, respectively). This result holds promise for GaN-bascd photodetectors operated under low temperatures, such as those seen in the space environment.