Strain-compensated (Ga,In)N/(Al,Ga)N/GaN multiple quantum wells for improved yellow/amber light emission

Abstract

XE examine the impact of the heterostructure design at the scale of the structural and optical properties for yellow light emissio

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

“…4 shows that the AlInN IL MQWs have enhancements that are similar to AlGaN IL MQWs. Although the AlGaN IL MQW is a more researched approach for high efficiency long wavelength emitters, [26][27][28][29][30][31] this data shows AlInN IL could still provide remarkable advantages owing to its high Al-content for better capping and smoothing effects for abrupt interface and add flexibility of tuning strain from tensile to compressive by changing In-content. Furthermore, the AlInN IL on top of InGaN QW serves as larger bandgap barrier, which, in principle, can suppress any electron leakage and enhance current injection efficiency.…”

“…The MQWs with AlGaN IL are samples from our previous report. 31 The growth sequence of the MQW with an AlInN IL is similar to MQWs with AlGaN ILs, [26][27][28][29][30][31] but with the additional challenge of changing growth pressures. Reported optimized growth pressures (P g ) for AlInN range from $20 to $50 Torr, [37][38][39][41][42][43][44] which is significantly lower than that of the InGaN QWs (P g $ 200 Torr).…”

“…[17][18][19] Several solutions have been proposed to enhance the efficiency of green-and red-emitting InGaN-based MQWs, including the use of large overlap QW active regions, [18][19][20][21] non-and semi-polar QWs, 22,23 ternary substrates, 24,25 and AlGaN interlayers (ILs) in InGaN MQW. [26][27][28][29][30][31] Specifically, AlGaN tensile barriers or ILs provide various benefits for higher efficiency green-red LEDs. [26][27][28][29][30][31] The AlGaN IL behaves as a "cap" layer that suppresses out-diffusion of indium from the InGaN QW and produces a more abrupt heterointerfaces.…”

“…[26][27][28][29][30][31] Specifically, AlGaN tensile barriers or ILs provide various benefits for higher efficiency green-red LEDs. [26][27][28][29][30][31] The AlGaN IL behaves as a "cap" layer that suppresses out-diffusion of indium from the InGaN QW and produces a more abrupt heterointerfaces. 26,27 It also enables strain compensation and promotes pseudomorphic growth with suppressed defect formation.…”

“…26,27 It also enables strain compensation and promotes pseudomorphic growth with suppressed defect formation. [29][30][31] Finally, the structure also enables annealing of InGaN QW during GaN barrier growth at higher temperatures that improves efficiencies. 27 AlInN is another potential IL choice for InGaN-based MQWs with potential advantages over AlGaN ILs.…”