Light emission by semiconductor structure with quantum well and array of quantum dots

A new type of composite active region of a laser, which contains an In0.2Ga0.8As quantum well (QW) and an array of InAs quantum dots (QDs) embedded in GaAs is studied. The QW acts as accumulator of injected carriers, and the QD array is the emitting system located in tunneling proximity to the QW. A theory for the calculation of electron and hole energy levels in the QD is developed. Occupation of the QDs due to the resonance tunneling of electrons and holes from the QW to the QD is considered; the conclusions are compared with the results obtained in studying an experimental laser with a combined active region.