A hybrid SiO 2 micro/nanospheres antireflection coating, deposited by a rapid convection deposition, acting as a passivation layer of GaN-based light-emitting diodes (LEDs) is studied in this paper. Since the critical angle could be enlarged by antireflection coating, Fresnel reflection could be reduced. In addition, due to the roughened surface of hybrid SiO 2 microsphere/nanosphere antireflection coating, the scattering effect could be increased. Thus, the light extraction efficiency could be further enhanced. As compared with a conventional LED (device A), at 20 mA, the studied device C exhibits 18.7% enhancement in light output power without any degradation of electrical properties. Reduced leakage current could also be achieved. Therefore, the use of hybrid SiO 2 microsphere/nanosphere antireflection coating could effectively improve the performance of GaN-based LEDs.
A switching device, with a p-type delta-doped sheet in the center of an InGaAs-GaAs quantum well, has been fabricated and demonstrated. An N-shaped negative-differential-resistance phenomenon resulting from the resonant-tunneling effect through the miniband is observed in the current-voltage measurement. From the experimental results, it is seen that the temperature plays an important role in device operation. The influences of temperature upon the peak-current voltage, valley-current voltage, peak-current density, and valley-current density are studied and discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.