Quantum-enhanced uniformity of carrier injection into successive quantum wells of multi-quantum-well structures

In multiple quantum well (MQW) structures carrier injection into distant quantum wells (QWs) described in a semi-classical way seems to be less effective than to closer ones. This may considerably affect performance of such MQW devices. Therefore, in the present paper a quantum-mechanical phenomenon, which may play a significant role in making the distribution of particles confined in a multi-well potential uniform, is presented. The time needed to distribute uniformly the particle is compared with the radiative lifetime in typical MQW lasers. Obtained results suggest that the described quantum-enhanced effect is in many cases effective enough to neglect originally non-uniform carrier injection into successive QWs of such a structure. It makes theoretical analysis of recombination phenomena in standard MQW diode lasers considerably easier.