CARRIER-INDUCED ENERGY SHIFT IN GAAS ALGAAS MULTIPLE-QUANTUM-WELL LASER-DIODES/

Emission energy shift due to high carrier density at threshold in mult iple quantum well (MQW) laser diodes is investigated theoretically. Th is energy shift is evaluated through the Schrodinger and the Poisson e quations self-consistently as well as the calculation of the gain spec tra with carrier-dependent lifetime broadening. The band filling and t he gain broadening effects show a blue shift on the emission energy. L arger number of wells, lower barrier height, or wider well thickness, reduces the blue shift dependence on the carrier density. At high inje ctions, this blue shift is offset by the bandgap shrinkage effect, whi ch displays smaller influence on MQW's. While the carrier density is f urther increased, the transition due to the second quantized state is found in single quantum wells, however it is difficult to be observed in MQW's.