Ultrasensitive Solar-Blind Detectors Weather Harsh Environments

A solar-blind ultraviolet photodetector (SBPD) designed for harsh environments uses amorphous gallium oxide (AGO) as a materials substitute for the traditional silicon substrate. Gallium oxide features a wide bandgap and high heat resistance, and it is capable of preserving SBPDs’ sensitivity. Amorphous gallium oxide is also easy to manufacture and integrate.

A group from University of Science and Technology of China of the Chinese Academy of Sciences developed the ultrasensitive SBPD.

Crystal structure of β-Gallium oxide. Courtesy of Orci/Wikimedia Commons CC BY-SA 3.0.

The team tailored its design to exhibit a high overall tolerance. It used defect and doping (DD) engineering, including the design of gallium-rich AGO, the annealing for recrystallization, and the doping supplementary. According to team members, the gallium-rich material helped deliver a high-response current and the ability to introduce doping supplementary. Nitrogen annealing contributed to photodetection via measures such as partial recrystallization and the formation of nanopores.

Tests showed that the material and nanopores specifically intensified solar-blind reactive currents. Crystallization, defect reduction, and doping supplementary weakened dark currents. Heated nitrogen toughened the film of gallium oxide. This enhanced its photoelectric performance and its tolerance to extreme conditions.

In general, the team reported, SBPDs based on DD engineering exhibited strong performance, which was characterized by high resistance. The method paves the way to design other photoelectric devices via the same means of engineering.

The research was published in Advanced Materials (www.doi.org/10.1002/adma.202106923).