Influence of an InGaN superlattice pre-layer on the performance of semi-polar (11–22) green LEDs grown on silicon

Abstract

It is well-known that it is crucial to insert either a single InGaN underlayer or an InGaN superlattice (SLS) structure (both with low InN content) as a pre-layer prior to the growth of InGaN/GaN multiple quantum wells (MQWs) served as an active region for a light-emitting diode (LED). So far, this growth scheme has achieved a great success in the growth of III-nitride LEDs on c-plane substrates, but has not yet been applied in the growth of any other orientated III-nitride LEDs. In this paper, we have applied this growth scheme in the growth of semi-polar (11-22) green LEDs, and have investigated the impact of the SLS pre-layer on the optical performance of semi-polar (11-22) green LEDs grown on patterned (113) silicon substrates. Our results demonstrate that the semi-polar LEDs with the SLS pre-layer exhibit an improvement in both internal quantum efficiency and light output, which is similar to their c-plane counterparts. However, the performance improvement is not so significant as in the c-plane case. This is because the SLS pre-layer also introduces extra misfit dislocations for the semipolar, but not the c-plane case, which act as non-radiative recombination centres.

Recent Progress in Long‐Wavelength InGaN Light‐Emitting Diodes from the Perspective of Epitaxial Structure

“…[ 62 ] Zhao et al inserted SL to semipolar green LEDs and found an improvement in IQE due to the reduced point defect density. [ 63 ] The IQE improvement for semipolar LED with SL was not significant as its c ‐pane counterparts because extra misfit dislocations were introduced as nonradiative recombination centers. The influence of thickness ratio of InGaN to GaN in prestrained structure was investigated by Qi et al Degraded crystal quality was observed in green LED with low thickness ratio, whereas LED with high thickness ratio showed high series resistance, indicating the importance of suitable design of prestrained structure.…”

Полуполярные Широкозонные III-N-слои На Кремниевой Подложке: Эпитаксия С Контролем Свойств Структур (Обзор)

“…Авторы [170][171][172] продемонстрировали, что светоизлучающие диоды GaN с длиной волны излучения около 530 nm могут быть синтезированы на полуполярном GaN (11−22), выращенном на структурированных подложках Si (113).…”

Effect of Asymmetric InAlGaN/GaN Superlattice Barrier Structure on the Optoelectronic Performance of GaN-Based Green Laser Diode

“…To enhance the optoelectronic performance of LD, researchers have made a lot of efforts in the direction of alleviating the strain accumulation in the active region and improving crystal quality. The commonly used methods include: growing a stress compensation layer in the active region before MQWs; 5,6 using ternary or quaternary compounds with the similarity to the lattice constants of InGaN as quantum barrier layer materials; 7,8 growing MQWs in the nonpolar or semipolar surfaces; 9 and doping GaN quantum barrier layer with silicon, etc. 10 These methods typically use a low indium content waveguide layer for good optical confinement.…”