Theoretical analysis of 630-nm band GaInP-AlGaInP strained quantum-well lasers considering continuum states

The spin-flip Raman scattering by the epitaxial layers of quaternary aluminium gallium indium phosphide alloys lattice matched to gallium arsenide has been investigated in order to gain insight into the band structure parameters of this material system. Both electron and hole spin-flip Raman signals were observed and were identified by their behaviour on the application of a biaxial strain to the epilayer. The gyromagnetic ratios of the electron and hole were determined and it was found that a three-band k • p model gives a good description of the experimental values of the conduction band gyromagnetic ratio as a function of composition; these data provide a new insight into the dependence of the spin-orbit splitting on composition.

Section: Resultsmentioning

confidence: 99%

Band structure parameters of quaternary phosphide semiconductor alloys investigated by magneto-optical spectroscopy

Griffin

Wolverson

Davies

et al. 2000

“…Specifically, the experimental curve fittings were performed using equation (1) in the current range of J < J at the maximum IQE (η IQE,MAX ) since the CIE takes 100% there. For the extraction of the fitting parameter, coefficient B was fixed at the theoretical values (1.0 × 10 −10 and 2.0 × 10 −11 cm 3 s −1 for the red and blue samples, respectively) [24,25], and A and C were allowed to vary while satisfying the following expression [26]:…”

Section: Efficiency Analysis Via Decouplingmentioning

confidence: 99%

Comparative study of III-phosphide- and III-nitride-based light-emitting diodes: understanding the factors limiting efficiency

Han

Lee²

2021

Modern light-emitting diodes (LEDs) require further improvements in the wall-plug efficiency (WPE). Thus, understanding and elucidating the physical factors limiting the WPE is of crucial importance. This study aims to understand and elucidate such factors via a comparative study of two different LED material systems, i.e. III-phosphide (AlGaInP) red and III-nitride (AlGaInN) blue LEDs. The WPE was decoupled into its component elements, which indicated that the dominant contribution to WPE reduction depends on the sample. To further investigate, thermodynamic and current component analyses were conducted. These analyses clearly demonstrated that the carrier dynamics is dependent of the material systems, i.e. internal quantum efficiency and voltage efficiency are simultaneously degraded due to the carrier accumulation in the blue sample. We found that the WPE can be improved using strategies dependent on the samples, such as improvement of the light extraction in the red sample and suppression of the carrier accumulation in the blue sample.

“…As discussed in section 2, Coulombic coupling involving unbound states above the quantum well edge can influence excitonic absorption. To simulate the contribution from such unbound states, the SQWs were placed within wide infinitely deep potential wells [6,[32][33][34][35]. This approximation has two effects.…”

Section: Inclusion Of Quasi-continuum States In Electroabsorption Sim...mentioning

confidence: 99%

The role of Coulombic coupling in electroabsorption of square quantum wells

Chen¹,

Earnshaw²,

Batty³

et al. 2001

The impact of Coulombic coupling between different subband pairs, on the quantum confined Stark effect in square quantum wells, has been studied. It is shown, via detailed comparison between electroabsorption spectra obtained from a full excitonic Green function calculation, a decoupled excitonic Green function calculation and measurement, that inclusion of the Coulombic coupling between different subband pairs is generally required for correct prediction of electroabsorption in square wells, especially for shallow or narrow square quantum wells. These results are of particular significance for the accurate calculation of electrorefraction, by Kramers-Kronig transformation, of quantum well electroabsorption spectra.