We have developed spectral models describing the electroluminescence spectra of AlGaInP and InGaN light-emitting diodes (LEDs) consisting of the Maxwell–Boltzmann distribution and the effective joint density of states. One spectrum at a known temperature for one LED specimen is needed for calibrating the model parameters of each LED type. Then, the model can be used for determining the junction...

Abstract We report the characterization of a N-polar InGaN layer deposited by metalorganic vapor-phase epitaxy on ScAlMgO 4 (0001) (SAM) substrate without low-temperature buffer layer. The was tensile-strained, and its stoichiometry corresponded to In 0.13 Ga 0.87 N. also present microstructural observation InGaN/SAM interface via integrated differential phase contrast-scanning transmission ele...

We investigate the effect of internal electric field in InGaN well layer of InGaN/GaN multiple quantum well light-emitting diodes (LEDs) on efficiency droop behavior. The simulation results show that the internal electric field in InGaN well layers of Ga-polar LEDs is same as the direction of external electric field by forward bias voltage, resulting in a strong efficiency droop. However, N-pol...

GaN green LED was grown on Si (111) substrate by MOCVD. To enhance the quality of InGaN/GaN MQWs, same-temperature (ST) GaN protection layers with different thickness of 8 Å, 15 Å, and 30 Å were induced after the InGaN quantum wells (QWs) layer. Results show that a relative thicker cap layer is benefit to get InGaN QWs with higher In percent at fixed well temperature and obtain better QW/QB int...

Abstract In this study, we present {11 2 ¯ 2} InGaN underlayers of high composition and multi-quantum wells (MQWs) grown using the m-plane sapphire substrate. Fully relaxed...

Molecular beam epitaxy growth of GaN and InGaN nanowires is accomplished on Si (111) substrates using Ga-droplet nucleation. Typical diameters range from 25-80 nm and lengths can be varied by increasing the growth time; the growth rate is ~0.25 microns/hour. The nanowires have been characterized structurally and optically. Photoluminescence spectra show band-edge emission of GaN nanowires cente...

Time-resolved cathodoluminescence (CL) techniques have been employed to examine the optical properties and kinetics of carrier relaxation in a InGaN/GaN single quantum well (QW) sample. CL images of the QW sample revealed a spotty cellular pattern indicative of local In compositional variations, which induce local potential fluctuations and result in a strong lateral excitonic localization at I...

The indium segregation in InGaN well layer is confirmed by a nondestructive combined method of experiment and numerical simulation, which is beyond the traditional method. The pre-deposited indium atoms before InGaN well layer growth are first carried out to prevent indium atoms exchange between the subsurface layer and the surface layer, which results from the indium segregation. The uniform s...

GaN and InGaN nanocolumns of various compositions are studied by roomtemperature photoluminescence (PL) under different ambient conditions. GaN nanocolumns exhibit a reversible quenching upon exposure to air under constant UV excitation, following a t time dependence and resulting in a total reduction of intensity by 85-90%, as compared to PL measured in vacuum, with no spectral change. This ef...