Solar-blind UV photodetector array spotlights efficacy of gallium oxide

Used for optical communication via light irradiation, solar-blind technology enables image generation through ultraviolet light. While optical technologies using other wavelengths must contend with interference from the sun, UV wavelengths are completely absorbed by the ozone layer. With background noise improvements, the technology may serve as a basis for highly efficient optoelectronic systems to advance functionality for the collective network of connected smart devices known as the Internet of Things.

Shen et al. fabricated a novel solar-blind UV photodetector array featuring wide bandgap gallium oxide (Ga₂O₃) wafers and demonstrated its efficacy.

“Benefiting from the unique response of Ga₂O₃ to solar-blind UV, the array makes UV communication come true,” said author Zeng Liu.

The fabrication is among the latest to feature gallium oxide, which has been used in other photodetector arrays with multi-functional usages from fingerprint recognition and image sensing to logic application and image storage.

The new setup demonstrated superior performance in metrics of photo-to-dark current ratio, responsivity, quantum efficiency, specific detectivity, and response time.

“The array has far more sensor units than a single device and can carry huge loads of information,” said Liu. “It can greatly reduce the time for information transmission. And it can transmit the information not only by encoding technology like traditional devices but also by transmitting continuous images and complete sentences. In other words, the types of information transfer have been enriched.”

The authors are planning to further their research in this area.

“The results verify our idea,” said Liu. “This means we will continue to promote further development of Ga₂O₃ optoelectronic array applications.”

Source: “Solar-blind UV communication based on sensitive β-Ga₂O₃ photoconductive detector array,” by Gaohui Shen, Zeng Liu, Chee-Keong Tan, Mingming Jiang, Shan Li, Yufeng Guo, and Weihua Tang, Applied Physics Letters (2023). The article can be accessed at http://doi.org/10.1063/5.0161521 .