Photoemission (UPS and XPS) study of local structures of amorphous GeTe and GeSe films

In situ photoemission (UPS and XPS) measurements have been performed for amorphous GeTe and GeSe films deposited onto a cooled substrate during thermal annealing and crystallization of the films. It has been found that an amorphous film prepared at room temperature has a 4-2 coordinated local structure while a highly disordered film deposited onto a 77 K substrate is largely 3-3 coordinated and relaxes into the 4-2 coordinated structure upon thermal annealing.