Piezoelectric and excitonic effects on optical properties of pseudomorphically strained wurtzite GaN quantum well lasers

Interband transitons of pseudomorphic GaN/Al _x Ga_{1- x} N quanturn wells are analized theoretically in detail with respect to the piezoelectric field utilizing full 6×6 Rashba-Sheka-Pikus (RSP) Hamiltonian. The modified band structure by the built-in Stark effect explains the presence of up to 400 meV shift of emission peaks in GaN/Alo,i₅Gao.₈sN. Also, the behaviors of quantum well exciton binding energies are calculated by the variational method and are discussed in terms of spatial separation of electron and holes by the built-in electric field.