Modification of exciton emission energies in InGaAs/AlInAs quantum wells by rapid thermal annealing

A spatially selective technique for modifying exciton energies in quantum wells by employing rapid thermal annealing and silicon dioxide capping is demonstrated in the InGaAs/AlInAs material system. Exciton emission energies in these quantum wells are blue shifted by as much as 60 meV after a 15 s rapid thermal anneal above 800 °C. The dependence of the energy shift on well width and annealing temperature is studied by measuring low-temperature photoluminescence spectra of single quantum wells. In contrast to the GaAs/AlGaAs case, a silicon dioxide film deposited on the surface inhibits the energy shift suggesting that a different mechanism is operating in the present material system.