Quantum-well intermixing influence on GaInNAs/GaAs quantum-well laser gain: theoretical study

Abstract

The effect of quantum-well intermixing on the material gain of a GaInNAs/GaAs quantum-well laser is investigated theoretically. The diffusion of gallium and indium atoms in the intermixed sample is assumed and their compositional profiles are modelled using Fick's law. The band-anti-crossing model is used to calculate the band structure of the GaInNAs quantum well, which is appropriate for this non-randomly-alloyed material system. The calculated results show good agreement with the observed photoluminescence excitation for both non-intermixed and intermixed samples, which confirms this model. It is found that the strain gradient, the variation of material band gap and the degeneracy between heavy and light holes are the main factors determining the quantized energy levels of the intermixed quantum well. With the increase of diffusion length, the material gain and differential gain decrease due to the increase of the conduction band effective mass and the rapid decrease of the dipole moments. These characteristics of quantum-well intermixing effects will be useful in the design of integrated photonic devices based on this material.

Modeling the intermixing effects in highly strained asymmetric InGaAs/GaAs quantum well

“…For the last decades, highly strained InGaAs/GaAs quantum wells (QWs) [1] have attracted considerable interest due to their fundamental physical properties and their potential capabilities for the fabrication of optoelectronic and photonic integrated circuits (PICs) [2,3] high-power semi-conductor diode lasers [4,5] and solar cells [6]. Due to its important role in adjusting the emission properties of quantum heterostructures, the interdiffusion process has been widely investigated theoretically and experimentally in various systems such as InGaAs/GaAs QW [7][8][9][10][11][12][13][14] However, the interface broadening and distortion of In-concentration profiles result from the well-known indium surface segregation in InGaAs/GaAs QW during the growth process.…”

Quantum Confinement Stark Effect of Different Gainnas Quantum Well Structures

“…This model successfully explains the increase of effective mass of dilute nitride semiconductors electrons is due to the repulsion from localized N states. It has been validated to predict the band structure and dipole moments of long wavelength emission lasers with quantum well intermixing structures [23][24] [25]. Due to its unique characteristics from N interaction, band structure will be affected by both N atoms and external electric field that applied to the QW.…”