Three types of textured indium-tin-oxide （ITO） surface, including nano-texturing and hybrid micro/nano-texturing with micro-holes （concave-hybrid-pattem） or micro-pillars （convex-hybrid-pattern）, were applied to...Three types of textured indium-tin-oxide （ITO） surface, including nano-texturing and hybrid micro/nano-texturing with micro-holes （concave-hybrid-pattem） or micro-pillars （convex-hybrid-pattern）, were applied to GaN-based light-emitting diodes （LEDs）. The nano-texturing was realized by maskless wet-etching, and the micro-texturing was achieved by standard photolithography and wet-etching. Compared to LED chips with flat ITO surface, those with nano-pattern, concave-hybrid-pattern, and convex-hybrid-pattern exhibit enhancement of 11.3%, 15.8%, and 17.9%, respectively, for the light-output powers at 20 mA. The electrical performance has no degradation. Moreover, the convex-hybrid-pattern show higher light-output efficiency under small injection current, while the concave-hybrid-pattern exhibit better light-output efficiency at large injection current. The light- extraction efficiency is simulated by use of two-dimensional finite difference time domain method, and the numer- ical results are consistent with the experiments.展开更多
As an alternative to the ultraviolet light-emitting diode(UV LED),the feasibility of utilizing UV micro-LED in the charge management in the detection of gravitational waves in space is experimentally studied.Compared ...As an alternative to the ultraviolet light-emitting diode(UV LED),the feasibility of utilizing UV micro-LED in the charge management in the detection of gravitational waves in space is experimentally studied.Compared with UV LED,micro-LED is more compact in size and has better current spreading,faster response time,and longer operating life.Performance characteristics of micro-LEDs were measured,with peak wavelengths of 254,262,274,and 282 nm for each respective micro-LED,and the photoelectric effect was demonstrated.The effectiveness of micro-LED-based charge management experiments was demonstrated using above micro-LEDs mounted on a cubical test mass,and different discharge rates were achieved by varying the drive current and duty cycle using pulse width modulation.Laboratory data were also shown to demonstrate the space qualification of the micro-LED device.The key electrical and optical characteristics of the micro-LEDs showed less than 5%variation.The results of the qualification bring the micro-LED device technology readiness level(TRL)to TRL-5.TRL-6 will be reached provided additional radiation and thermal tests are conducted and in a position ready to be flown and further tested in space.展开更多
基金Project supported by the National High Technology Research and Development Program of China(No.2014AA032609)the Strategic Emerging Industry Special Funds of Guangdong Province(Nos.2010A081002009,2011A081301004,2012A080302003)the Fundamental Research Funds for the Central Universities(Nos.2013ZM093,2013ZP0017)
文摘Three types of textured indium-tin-oxide （ITO） surface, including nano-texturing and hybrid micro/nano-texturing with micro-holes （concave-hybrid-pattem） or micro-pillars （convex-hybrid-pattern）, were applied to GaN-based light-emitting diodes （LEDs）. The nano-texturing was realized by maskless wet-etching, and the micro-texturing was achieved by standard photolithography and wet-etching. Compared to LED chips with flat ITO surface, those with nano-pattern, concave-hybrid-pattern, and convex-hybrid-pattern exhibit enhancement of 11.3%, 15.8%, and 17.9%, respectively, for the light-output powers at 20 mA. The electrical performance has no degradation. Moreover, the convex-hybrid-pattern show higher light-output efficiency under small injection current, while the concave-hybrid-pattern exhibit better light-output efficiency at large injection current. The light- extraction efficiency is simulated by use of two-dimensional finite difference time domain method, and the numer- ical results are consistent with the experiments.
基金supported by the National Key R&D Program of China(Task No.2021YFC2202500).
文摘As an alternative to the ultraviolet light-emitting diode(UV LED),the feasibility of utilizing UV micro-LED in the charge management in the detection of gravitational waves in space is experimentally studied.Compared with UV LED,micro-LED is more compact in size and has better current spreading,faster response time,and longer operating life.Performance characteristics of micro-LEDs were measured,with peak wavelengths of 254,262,274,and 282 nm for each respective micro-LED,and the photoelectric effect was demonstrated.The effectiveness of micro-LED-based charge management experiments was demonstrated using above micro-LEDs mounted on a cubical test mass,and different discharge rates were achieved by varying the drive current and duty cycle using pulse width modulation.Laboratory data were also shown to demonstrate the space qualification of the micro-LED device.The key electrical and optical characteristics of the micro-LEDs showed less than 5%variation.The results of the qualification bring the micro-LED device technology readiness level(TRL)to TRL-5.TRL-6 will be reached provided additional radiation and thermal tests are conducted and in a position ready to be flown and further tested in space.
