GaN grown on nano-patterned sapphire substrates

Abstract

High-quality gallium nitride (GaN) film was grown on nano-patterned sapphire substrates (NPSS) and investigated using XRD and SEM. It was found that the optimum thickness of the GaN buffer layer on the NPSS is 15 nm, which is thinner than that on micro-patterned sapphire substrates (MPSS). An interesting phenomenon was observed for GaN film grown on NPSS:GaN mainly grows on the trench regions and little grows on the sidewalls of the patterns at the initial growth stage, which is dramatically different from GaN grown on MPSS. In addition, the electrical and optical properties of LEDs grown on NPSS were characterized.

Improved light extraction efficiency of GaN-based flip-chip light-emitting diodes with an antireflective interface layer

“…1-3 Use of NPSS is an effective method to enhance both the internal quantum efficiency (IQE) by lower threading dislocation density [4][5][6][7] and light extraction efficiency (LEE) of LEDS. 8 Flip-chip (FC)-LEDs are becoming increasingly popular as a means to facilitate chip-level integration and achieve high power and efficiency.…”

Comparative study of epitaxial growth and Ni/GaN Schottky device on patterned sapphire substrates

“…16,17 However, only a few reports have addressed GaN growth on PSS in the application of SBDs. The different-sized PSS are widely used to optimize a light-emitting device, [18][19][20] which is beneficial to improve the efficiency of light extraction. [21][22][23][24] In this work, we compare the epitaxial quality, surface state and stress of GaN materials on different PSSs.…”

“…16,17 However, only a few reports have addressed GaN growth on PSS in the application of SBDs. The different-sized PSS are widely used to optimize a light-emitting device, 18–20 which is beneficial to improve the efficiency of light extraction. 21–24…”

Application of nano-patterned InGaN fabricated by self-assembled Ni nano-masks in green InGaN/GaN multiple quantum wells

“…Since the first GaN-based blue light emitting diode (LED) was made by Shuji Nakamura in 1993 [1] , the LEDs based on Group III-nitride materials developed rapidly and were widely used. However, there has been no solution to the "green gap", which describes the low efficiency of green LEDs, yet blue and red LEDs achieve relatively high efficiency luminescence [2,3] . One of reasons account for the above problem is the increase of indium component of In x Ga 1-x N/GaN multiple quantum wells (MQWs), while the increase is necessary to enable InGaN-based LEDs to be luminous with longer wavelengths.…”