Density of states for dilute nitride systems: calculation of lifetime broadening

We present calculations for the band structure of bulk and confined quantum well and quantum wire GaInNAs structures. To treat this non-randomly alloyed material system we follow previous approaches in using an Anderson impurity model where the nitrogen localized states interact with the GaInAs conduction band states. We solve this model using Matsubara Green&psila;s functions and the associated self-energies which produce a complex band structure where both the real and imaginary components depend on the concentration of nitrogen. In particular this approach gives a definite nitrogen dependent lifetime broadening and is different from previous work in that no artificial input parameters are used. The density of states of the conduction band, derived from these functions, is strongly altered by interaction with the nitrogen states. The density of states is required for further optical and transport investigations involving this system.