Characterisation of molecular beam epitaxy-grown InGaAs multilayer structures using photoluminescence

Molecular beam epitaxy-grown InGaAs/GaAs multilayer structures were used to characterise for their indium composition, quantum well widths and energy levels in quantum wells employing low-temperature photoluminescence spectro scopy. The effect of surface segregation and thermal desorption of indium a toms in these structures which changes the intended square well and barrier profiles is demonstrated. These shape changes in the well and barrier must be taken into account to correctly predict the quantum well energy level p ositions and hence the indium composition and the quantum well width. (C) 2 001 Elsevier Science Ltd. All rights reserved.