A theoretical investigation of the band alignment of type-I direct band gap dilute nitride phosphide alloy of GaN _x As _y P _{1– x–y} /GaP quantum wells on GaP substrates

Abstract

The GaP-based dilute nitride direct band gap material Ga(NAsP) is gaining importance due to the monolithic integration of laser diodes on Si microprocessors. The major advantage of this newly proposed laser material system is the small lattice mismatch between GaP and Si. However, the large threshold current density of these promising laser diodes on Si substrates shows that the carrier leakage plays an important role in Ga(NAsP)/GaP QW lasers. Therefore, it is necessary to investigate the band alignment in this laser material system. In this paper, we present a theoretical investigation to optimize the band alignment of type-I direct band gap GaN x As y P 1−x−y /GaP QWs on GaP substrates. We examine the effect of nitrogen (N) concentration on the band offset ratios and band offset energies. We also provide a comparison of the band alignment of type-I direct band gap GaN x As y P 1−x−y /GaP QWs with that of the GaN x As y P 1−x−y /Al z Ga 1−z P QWs on GaP substrates. Our theoretical calculations indicate that the incorporations of N into the well and Al into the barrier improve the band alignment compared to that of the GaAsP/GaP QW laser heterostructures.

Achieving carrier and photon confinement in Ga(NAsP)/AlGaP/GaP QWs on Si substrates

“…With the incorporation of nitrogen (N) into GaAs 1−y P y alloy, these physical properties have been changed significantly and these major challenges are overcome [4]. Arsenide (As)-rich dilute nitride Ga(NAsP) is lattice matched to GaP and hence Si substrates with a direct band gap [5,6].…”

Excitonic transitions in Be-doped GaAs/AlAs multiple quantum well

“…Quasi-two-dimensional semiconductor-based quantum well and superlattice structures have extensively been investigated because of their potential applications in compact Terahertz emitters, cascade lasers, small-size detectors, etc. [1][2][3][4][5] A characteristic feature of the optical spectra of quantum well and superlattice systems at low temperatures is the occurrence of excitons. The exciton is often treated as a 'two-body' combination involving an electron and a hole between which there is Coulombic interaction.…”

“…where r 2 ⊥ = (x e − x h ) 2 + (y e − y h ) 2 . In a quantum well or superlattice structure, the problem is complicated by the quantum-well confined potential existing along the z-direction.…”