Bulk GaN based violet light-emitting diodes with high efficiency at very high current density

Dislocation related droop in InGaN/GaN light emitting diodes investigated via cathodoluminescence

“…At the same current density, the droop demonstrated in Ref. 13, where low dislocation density bulk GaN substrates were used, is just about 5% (see Fig. 3 in Ref.…”

“…In fact there are examples of LEDs with a low droop published in the recent literature, in these cases they were typically grown on a low dislocation density bulk GaN substrate. 13,14 If we take the cases where the dislocation density is around or below 10 6 cm À2 , we may assume that the dislocation influence on droop can be neglected, and the residual droop in such cases may be understood to be Fig. 3(b) corresponding to areas with lower and higher dislocation density, respectively.…”

Improved performance of GaN based light emitting diodes with ex-situ sputtered AlN nucleation layers

“…Moreover, in these two cross-sectional TEM images [ Fig. 3(b) and 3(d)], the g vectors of samples A and B were both g= [11][12][13][14][15][16][17][18][19][20]. The edge-type dislocations were also identified in these two images, which were marked by red circles.…”

A design of a PhC-enhanced LED for electroluminescence cooling

“…20 Moreover, people also apply the surface texturing technology for volumetric LEDs with the dies usually shaped into special geometries and encapsulated, with the EQE exceeding 90%. 13,22 Another method to extract photons in LEDs is to etch photonic crystal (PhC) structure onto the emission surface. (Fig.…”