The electrical properties of amorphous GeTe films deposited at room temperature, ion implanted, and melt-quenched have been studied. The activation energy for the mobility gap varies from 0.64, in the melt-quenched, to 0.74 eV, in the as deposited film. In all the types of amorphous, pre-annealing at temperatures below crystallization induces relaxation, increasing the resistance and the mobility gap. Pre-annealing also reduces the nucleation rate for crystallization by a factor up to 4. A model is proposed, describing the competing processes of structural relaxation and crystallization, as governed by a population of sub-critical nuclei formed by medium range ordered regions.
American Institute of Physics
12 Aug 2013
Volume: 103 Issue: 7 Pages: 071901
Applied Physics Letters