Strong exciton energy blue shift in annealed Si/SiO2 single quantum wells

A theoretical study is presented on how the annealing-induced interfacial t ransition region changes the confined ground state exciton in Si/SiO2 singl e quantum wells (QWs). The interface thickness and the mean well width conf inement depend on the time and temperature of annealing, as well as on the diffusion coefficient of oxygen in silicon. It is shown that an annealing-r elated interface width increase of a few Angstroms can strongly blue shift (hundreds of milli-electron volts) the confined ground state exciton energy in Si/SiO2 single quantum wells. The results allow to suggest that anneali ng processes can be used to tune (from red to blue) the light emission in S i/SiO2 single quantum wells. (C) 2000 Elsevier Science B.V. All rights rese rved.