Abstract
Photoluminescence spectroscopy has been employed in previous studies of semiconductor quantum wells and of buried interfaces in heterostructures. Nevertheless, the low amplitude of the signals collected, and the experimental difficulties, have limited the analyses to samples made on purpose.On the contrary, in this work, the analyses at room temperature and at 4 K of a commercial MESFET and of a commercial HEMT are presented. With the performed experiments, new informations about the composition of these components were achieved; in particular signals from deep levels and from the Cr states of the HEMT substrate were detected.After further studies on the shape of the spectra, the photoluminescence could probably be employed in reliability assessments to show the modifications in the semiconductor layer composition and in the shape of the heterostructure's surfaces of single devices.