Y. J. Lee

Abstract: GaN-based light-emitting diodes (LEDs) with emitting wavelength of 450 nm were grown on patterned sapphire substrates (PSSs) fabricated by chemical wet etching The crystallography-etched facet was {1-102} R-plane with a 57deg against {0001} C-axis and had superior capability for enhancing light extraction efficiency The light output power of the PSS LED was 115 times higher than that of the conventional LED at an injection current of 20 mA The output power and external quantum efficiency were estimated to be 9 mW and 164%, respectively The improvement was attributed not only to geometrical shapes of {1-102} crystallography-etched facets that efficiently scatter the guided light to find escape cones, but also to dislocation density reduction by adopting the PSS growth scheme

TL;DR: In this article, the authors investigated the mechanisms of the excitation power dependent internal quantum efficiency in InGaN/GaN multiple quantum wells (MQWs) LEDs grown on the planar and the patterned sapphire substrates (PSS) at temperature of 15 and 300 K.

TL;DR: An n-side-up AlGaInP-based light-emitting diode (LED) with a triangle-like surface morphology was fabricated using the adhesive layer bonding technique, followed by wet etching to roughen the surface as mentioned in this paper.

TL;DR: In this paper, a patterned sapphire substrate (PSS) with a parallel stripe along the 1 1 1 ¯ 0 0 0 ǫ -direction was used to produce a 20% higher output power than the conventional LEDs.

TL;DR: In this paper, a high light-extraction 465nm GaN-based vertical light-emitting diode structure with double diffuse surfaces was presented, where the external quantum efficiency was demonstrated to be about 40% and the high performance LED was achieved mainly due to the strong guided-light scattering efficiency.