Views: 1 Author: Site Editor Publish Time: 2022-06-01 Origin: Site
In the past two years, UV light technology has become well-known to the public for its high-efficiency disinfecting of the new coronavirus during the epidemic. Then, more ultraviolet light technology fields such as printing curing, coin anti-counterfeiting, skin disease treatment, and plant growth lighting have gradually been discovered by various industries including the lighting industry. At the same time, the staff of various scientific research institutions are constantly exploring innovative application modes of ultraviolet light technology, and use the power of light technology to promote the high-quality development of society and people's livelihood.
Through the display and inventory of the top ten cutting-edge ultraviolet light scientific and technological achievements in the country, we have brought important direction and reference for the development of enterprises and institutions engaged in the research, production and sales of this new optical technology.
1. High brightness, high modulation bandwidth deep ultraviolet Micro-LED array
In April this year, Peking University, Songshan Lake Materials Laboratory, Fudan University, and Dongguan Zhongjing Semiconductor Co., Ltd. jointly used the array interconnection micronization technology route to successfully realize the development of high-brightness, high-modulation bandwidth deep ultraviolet Micro-LED arrays.
During the fabrication of the array, the researchers developed a device fabrication strategy for interconnected array planar Micro-LEDs (PAP-μLEDs), which improved the current spreading and stress distribution uniformity. It solves the problems of traditional large-size LED current crowding and light absorption loss inside the device, and weakens the Transverse-magnetic (TM) mode light output caused by the transition of tensile stress, further improving the light extraction efficiency. Collective improvements in brightness, electro-optical conversion efficiency, and modulation bandwidth at high injection current densities are achieved.
The release of this scientific research achievement is expected to greatly improve the device performance of industrialized deep ultraviolet LEDs and expand its application fields, and realize the integration of cross-domain application functions such as sterilization and solar-blind communication.
2. Artificial Nanostructures for Enhanced Deep Ultraviolet Light Extraction
In March of this year, a research team from Xiamen University innovatively designed a chamfered pyramid/table-shaped artificial nanostructure, which can greatly improve the extraction efficiency of deep ultraviolet light.
The researchers combined nano-imprinting, dry etching technology and wet etching process to form (0001), (10-13) on the (AlN)8/(GaN)2 active layer with an emission wavelength as short as 234 nm. And (20-21) and other groups of crystal planes with finely controllable angles. These crystal planes can control the propagation and extraction mode of deep ultraviolet light waves in nanostructures, effectively breaking through the limitation of small cone angles of outgoing light in traditional planar structures. After the introduction of a chamfered pyramid/table structure with controllable crystal planes, the TM and TE polarized light are enhanced by 5.6 times and 1.1 times, respectively, compared with the planar structure, and the total luminescence intensity at the deep ultraviolet wavelength of 234 nm is increased by nearly 2 times.
The publication of the research results will provide new ideas for improving the efficiency of deep ultraviolet short-wave light-emitting devices, and is expected to enable optoelectronic devices such as micro-sized LEDs and deep ultraviolet detectors to have better optical properties.
