Optical properties of InAs/InP ultrathin quantum wells

The optical properties of ultrathin InAs impurity layers embedded in bulk InP are investigated. Our calculations are based on a tight-binding description of the electronic structure, with spin-orbit interactions and strain effects included in a consistent manner. It is shown that the energy gap increases with decreasing number of InAs monolayers. In the limit of a single InAs monolayer, the energy gap is found to be 120 meV less than that of bulk InP. Our results are in good agreement with experimental data as far as the heavy-hole-electron transition is concerned. The energy difference between optical transitions is, however, in disagreement with both experiment and effective-mass calculations. (C) 2001 Elsevier Science B.V. All rights reserved.