Abstract
A reduction of the threshold current density of InGaN quantum well (QW) lasers is found from the usage of AlGaInN barriers. Large bandgap and strain-managing AlGaInN barriers surrounding the InGaN quantum wells’ (QWs) active regions are investigated via the 6-band self-consistent k·p formalism for their spontaneous emission, material gain, and threshold current density properties. In this study, quaternary AlGaInN alloys both lattice-matched and tensile-strained to GaN, with bandgaps ranging from 3.4 eV to 5.2 eV, are employed as thin barriers (∼1 nm) surrounding the InGaN active region. The AlGaInN barriers provide strong carrier confinement, which improves the electron and hole wavefunction overlap by ∼25%, while simultaneously reducing the strain relaxation in the active region. This study shows that InGaN QWs surrounded by AlGaInN barriers improve the material gain by ∼30%, reduce the threshold carrier density by ∼18%, and reduce the threshold current density by ∼40% over the conventional InGaN/GaN QW structure. Our results indicate that the AlGaInN barriers substantially enhance the radiative efficiency and reduce the power consumption for light emitting diodes (LEDs) and laser diodes (LDs), making them very attractive candidates for the design of low threshold optoelectronic devices.
Highlights
INTRODUCTIONThe InGaN-based diode lasers and light emitting diodes (LEDs) have received tremendous attention owing to versatile applications in high-density optical storage devices, portable laser projectors, and full color displays. The active regions of conventional InGaNbased lasers and LEDs primarily consist of InGaN-based quantum well (QW) structures with GaN barriers. The incorporation of InGaN/GaN multiple quantum wells’ (QWs) as the active region for blue-emitting LEDs has made bright and energy-saving white light sources possible today, a critical breakthrough for which the 2014 Nobel Prize in Physics was awarded
The InGaN-based diode lasers and light emitting diodes (LEDs) have received tremendous attention owing to versatile applications in high-density optical storage devices, portable laser projectors, and full color displays.1–6 The active regions of conventional InGaNbased lasers and LEDs primarily consist of InGaN-based quantum well (QW) structures with GaN barriers.7–10 The incorporation of InGaN/GaN multiple quantum wells’ (QWs) as the active region for blue-emitting LEDs has made bright and energy-saving white light sources possible today, a critical breakthrough for which the 2014 Nobel Prize in Physics was awarded.11Despite the great success of the InGaN-based technology in solid-state lighting, the performance of conventional InGaN QWs is still limited by three major factors
Our study shows a significant enhancement of the optical gain and spontaneous emission rate properties for the In0.28Ga0.72N QW with AlxGayIn1-x-yN barriers over those of the conventional InGaN/ GaN QW structure
Summary
The InGaN-based diode lasers and light emitting diodes (LEDs) have received tremendous attention owing to versatile applications in high-density optical storage devices, portable laser projectors, and full color displays. The active regions of conventional InGaNbased lasers and LEDs primarily consist of InGaN-based quantum well (QW) structures with GaN barriers. The incorporation of InGaN/GaN multiple QWs as the active region for blue-emitting LEDs has made bright and energy-saving white light sources possible today, a critical breakthrough for which the 2014 Nobel Prize in Physics was awarded.. The active regions of conventional InGaNbased lasers and LEDs primarily consist of InGaN-based quantum well (QW) structures with GaN barriers.. Previous numerical studies have reported an enhancement of the spontaneous emission rate and material gain for InGaN-based QWs with thin Al0.2Ga0.8N barrier layers.. The growth of lattice-matched AlInN/GaN layers by metalorganic vapor phase epitaxy (MOVPE) has been reported.35 Many of these methods have successfully enhanced the PL emission of the QWs and serve as a motivation for this work. The potential for thin barriers to enhance the radiative recombination rate and reduce the threshold current density is of great importance for InGaN-based LEDs and lasers. Our study shows a significant enhancement of the optical gain and spontaneous emission rate properties for the In0.28Ga0.72N QW with AlxGayIn1-x-yN barriers over those of the conventional InGaN/ GaN QW structure. Such a result motivates a thorough experimental exploration of the improvement AlGaInN barriers can have on nitride-based optoelectronic devices
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
