Electronic band structure and material gain of dilute nitride quantum wells grown on inp substrate

Abstract

The eight-band kp Hamiltonian is applied to calculate electronic band structure and material gain in dilute nitride quantum wells (QWs) grown on InP substrate. Three N-containing QW materials (GaInNAs, GaNAsSb, and GaNPSb) and different N-free barriers (GaInAs, GaAsSb, GaPSb, AlGaInAs, GaInPAs, AlGaAsSb, GaPAsSb, and AlGaPSb) lattice matched to InP are analyzed. It is shown that Ga 0.17 In 0.83 N y As 1-y -QWs with Ga 0.47 In 0.53 As, Al 0.23 Ga 0.24 In 0.53 As, or Ga 0.17 In 0.83 P 0.63 As 0.37 barriers are a very good gain medium for long-wavelength lasers grown on InP substrates. For N-free QWs the transverse electric (TE) mode of the material gain develops at 2.1 mu textm. This gain peak shifts toward longer wavelengths upon the incorporation of nitrogen and reaches the wavelength of sim 2.8~mu textm for 3% N. For GaN y As 0.26-y Sb 0.74 -QWs no quantum confinement or very weak quantum confinement exist for electrons in N-free QWs with the ternary barrier (i.e., GaAs 0.51 Sb 0.49) and quaternary (Al 0.23 Ga 0.77 As 0.51 Sb 0.49 and GaP 0.25 As 0.15 Sb 0.60) barriers, respectively. However, the quantum confinement in the conduction band strongly increases after incorporation of nitrogen. For GaN y As 0.26-y Sb 0.74 -QWs with 3% N gain peak for TE mode exists at 3.2 mutextm. Very similar changes in electronic band structure and material gain are noticed for GaN y P 0.26-y Sb 0.74 -QWs with GaP 0.35 Sb 0.65, Al 0.23 Ga 0.77 As 0.52 Sb 0.48, and GaP 0.25 As 0.15 Sb 0.60 barriers. In that case gain peak (TE mode) for GaN 0.03 P 0.23 Sb 0.74 -QW with GaP 0.35 Sb 0.65 barrier is at 3.6 mu textm. The intensity and the shape of material gain spectra in the three QW system vary with changes of the nitrogen concentration and the barrier content. At carrier concentration of 5times 1018 cm-3 , the largest material gain exists for Ga 0.17 In 0.83 N y As 1-y -QWs with Al 0.23 Ga 0.24 In 0.53 As and Ga 0.17 In 0.83 As 0.37 Ga 0.63 barriers.