According to sources, on March 26th, researchers Chen Zhitao and Zhao Wei from the Semiconductor Research Institute of the Guangdong Provincial Academy of Sciences have made new progress in the field of low-cost, high-efficiency deep ultraviolet light-emitting structure fabrication, with support from projects such as the National Key R&D Program and the National Natural Science Foundation. Their relevant findings were published in "Crystal Growth & Design" and selected as the cover feature for the current issue.
Journal Cover for Current Issue. Image Provided by Interviewee
Gallium Nitride-Based Deep Ultraviolet Light-Emitting Diodes (LEDs) offer numerous advantages such as mercury-free emission, low voltage operation, compact size, and integration feasibility, making them widely applicable in fields like public health, environmental protection, biochemical sensing, medical, and defense. However, the current efficiency of aluminum gallium nitride-based deep ultraviolet LEDs is extremely low (typically <10%), significantly hindering the industrial development and market application of these devices. High Al composition, aluminum gallium nitride defects, strain, and difficulties in quantum confinement control are among the critical reasons.
Addressing the aforementioned challenges, researchers have developed a low-cost, high-efficiency deep ultraviolet light-emitting structure growth method using metalorganic chemical vapor deposition equipment. Specifically, a 400 nm thick ultra-thin aluminum nitride-based epitaxial layer is grown on a substrate with a large tilt angle, achieving high crystal quality while effectively suppressing residual strain through macro-step-induced dislocation tilting and interaction. Furthermore, by utilizing the difference in incorporation efficiency of Al and Ga atoms at the edges and terraces of macro-steps, a high density of quantum wires is introduced into the conventional quantum well structure, effectively enhancing radiation recombination efficiency. As a result, the internal quantum efficiency of 280nm emission reaches 70%, laying a material foundation for low-cost, high-efficiency deep ultraviolet light-emitting devices.
For more information, refer to the related paper: https://doi.org/10.1021/acs.cgd.3c00990
