Capture area in quantum well structures

Carrier capture in quantum well structures defines the rate properties of the lasers and amplifiers based on them. The space dependence of the carrier capture rate is investigated. The capture area is introduced from first principles, not as a geometric parameter of a heterosystem, but as a fundamental characteristic of the quantum well structure following from its quantum nature. Computations for the asymmetrical multiple quantum well heterostructure a show lack of fit for the plane wave approximation often used for simulation of bulk-like quasicontinuum states under investigation of the carrier capture processes. Results obtained suggest the necessity of taking into account the dependence of the capture area on the composition of a QW structure, as well as on the position of the device operating point.