Integrating AlInN interlayers into InGaN/GaN multiple quantum wells for enhanced green emission

Abstract

Significant enhancement in green emission by integrating a thin AlInN barrier layer, or interlayer (IL), in an InGaN/GaN multiple quantum well (MQW) is demonstrated. The MQWs investigated here contains 5 periods of an InGaN QW, a 1 nm thick AlInN IL, and a 10 nm thick GaN barrier grown by metalorganic chemical vapor deposition. To accommodate the optimum low-pressure (20 Torr) growth of the AlInN layer a growth flow sequence with changing pressure is devised. The AlInN IL MQWs are compared to InGaN/AlGaN/GaN MQWs (AlGaN IL MQWs) and conventional InGaN/GaN MQWs. The AlInN IL MQWs provide benefits that are similar to AlGaN ILs, by aiding in the formation of abrupt heterointerfaces as indicated by X-ray diffraction omega-2theta (x-2h) scans, and also efficiency improvements due to high temperature annealing schedules during barrier growth. Room temperature photoluminescence of the MQW with AlInN ILs shows similar performance to MQWs with AlGaN ILs, and $4-7 times larger radiative efficiency (pump intensity dependent) at green wavelengths than conventional InGaN/GaN MQWs. This study shows the InGaN-based MQWs with AlInN ILs are capable of achieving superior performance to conventional InGaN MQWs emitting at green wavelengths.

Effect of Dielectric Distributed Bragg Reflector on Electrical and Optical Properties of GaN-Based Flip-Chip Light-Emitting Diodes

“…The improvement of IQE has played a key role in LED development. Specifically, the IQE of the InGaN LEDs have been improved by using the large overlap quantum well concept or the new active material concept [17,18,19,20]. Generally, LEDs should be driven at a high current density to obtain higher light output power (LOP), which also inevitably generates a large portion of heat [21].…”

III‐Nitride Micro‐LEDs for Efficient Emissive Displays

“…It is possible that further optimization or more creative IL schemes could lead to further gains. For example, recently it has been shown that ILs formed from AlInN can be used, and these structures exhibit efficiency gains that are similar to AlGaN ILs …”

“…One approach for higher efficiency longer wavelength InGaN LEDs that has produced record efficiencies at green gap wavelengths is the use of AlGaN interlayers in the multiple quantum well (MQW) active layer. [87,96,[121][122][123][124][125][126][127] This is most interesting in the green and red because of demonstrated record external quantum efficiencies of 25% at 550 nm [125] and 2.5% at 608 nm. The AlGaN interlayer (IL) is grown on top of the InGaN quantum well as shown in Figure 5a.…”

“…For example, recently it has been shown that ILs formed from AlInN can be used, and these structures exhibit efficiency gains that are similar to Al-GaN ILs. [127] Another option is to use nanostructures to achieve efficient long wavelength emission, exploiting the partial strain compensation that can occur. One possibility is to use nanowires which have exhibited higher In content InGaN QWs.…”

Modeling the Output Performance of Al0.3Ga0.7As/InP/Ge Triple-Junction Solar Cells for a Venus Orbiter Space Station

“…To power this hypothesized space station, a high-efficiency solar cell based on the combination of III-V groups solar cells like GaInP, GaInAs, AlGaAs, InP, and GaAs might be used in the form of multijunction solar cells (MJSC). The unique electronic structure of III-V based materials had long been known to have a wide range of applications, such as in quantum wells LED [18][19][20][21][22][23], laser [24], sensors [25], and also solar cells [26][27][28][29][30][31]. Those III-V groups solar cells are known for their ability to withstand harsh conditions in the outer space, such as energetic particles and high temperature [32][33][34][35].…”