Nitride dot-in-nanowire light emitters with suppressed auger process

• Published in: Optical materials 2020-01, Vol.99, p.109610, Article 109610
• Main Authors: Wu, Ye, Zhang, Zi-Chang, Ahmed, Shaikh
• Format: Article
• Language: English
• Subjects: Atomistic simulation; Auger recombination; Dot-in-nanowire structures; Efficiency droop; III-Nitride emitters; Interface grading
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2019.109610

In wurtzite III-Nitride nano-devices, the non-radiative Auger recombination is the primary mechanism responsible for the degradation of internal quantum efficiency (IQE), especially under high current density. In this paper, by employing an atomistic tight-binding framework, we theoretically study the effects of Auger recombination in recently reported InGaN/GaN dot-in-nanowire light emitters. The effects of strain and polarization, which can be strong in realistically-sized structures, have been considered. We demonstrate that the use of graded interfacial confinement leads to a weaker Auger recombination as compared to the abrupt counterpart, especially for thinner nanowires. The atomistically simulated Auger recombination coefficient for the core quantum dot buried in nanowire with different diameter is then incorporated into a TCAD simulator to obtain the device terminal (efficiency vs. current) characteristics. Overall, the simulation results indicate that increasing the diameter of the host nanowire (that is, the volume of the active region) remains the most efficient way to suppress Auger recombination. •Million-atom study of Auger degradation in InGaN/GaN dot-in-nanowires.•Multiscale modeling using coupled tight-binding-VFF-Poisson-TCAD framework.•Grading of confining potential is a potential solution, especially for thin structures.•Devices with large diameter are affected least by Auger recombination process.•Detailed analysis using the atomicity and granularity of wavefunction distributions.