Modulation Doping Effect in the Optical Gain of Type-II GaAsSb/GaAs Quantum-Well Structures

Modulation Doping Effect in the Optical Gain of Type-II GaAsSb/GaAs Quantum-Well Structures

The effect of modulation doping on the optical gain characteristics of type-II GaAsSb/GaAs quantum-well (QW) lasers was investigated using a self-consistent method. The interband transition energy gradually increased with n-type modulation doping. However, in the case of p-type modulation doping, the rate of increase was found to be smaller than that of n-type modulation doping. The optical gain was found to be largely enhanced by an increasing n-type modulation doping density. This could be explained by the fact that the optical matrix element was greatly increased due to the band-bending effect. On the other hand, in the case of p-type modulation doping, the optical gain was slightly smaller than that for n-type modulation doping because the optical matrix element was reduced by the negative charge from the ionized acceptors near the well.

The effect of modulation doping on the optical gain characteristics of type-II GaAsSb/GaAs quantum-well (QW) lasers was investigated using a self-consistent method. The interband transition energy gradually increased with n-type modulation doping. However, in the case of p-type modulation doping, the rate of increase was found to be smaller than that of n-type modulation doping. The optical gain was found to be largely enhanced by an increasing n-type modulation doping density. This could be explained by the fact that the optical matrix element was greatly increased due to the band-bending effect. On the other hand, in the case of p-type modulation doping, the optical gain was slightly smaller than that for n-type modulation doping because the optical matrix element was reduced by the negative charge from the ionized acceptors near the well.