Redshift of the light emission from highly strained In0.3Ga0.7As∕GaAs quantum wells by dipole δ doping

Abstract

We have studied theoretically the energy band structures and optical properties of highly strained dipole δ-doped In0.3Ga0.7As∕GaAs single quantum wells. Including dopant diffusion effect, strain in the quantum well, spin-orbital interactions, and many-body effects, the self-consistent calculations of the eight-band k∙p model and the Poisson equation show that the dipole δ doping induces an electric field across the In0.3Ga0.7As quantum well by the Stark effect so that both the interband transition energy and the wave-function overlap between the ground-state electrons and holes are reduced. Applying an external bias across the quantum well partially cancels the built-in electric field and reduces the wavelength redshift. The calculated material gain peak is close to the experimental lasing wavelength.