Thermal equilibrium processes in carbon-based amorphous semiconducting ternary alloys

Abstract

This paper deals with the metastability of as-deposited a-CSiGe: H alloys. We look essentially at room-temperature dark conductivity of samples, both as deposited and after annealing cycles. Samples were subjected to thermal annealing cycles at increasing temperatures up to around 300°C. The results are analysed from the point of view of the freezing temperature and stretched-exponential structural relaxation. To apply this last analysis, a new approach for non-isothermal relaxation had to be introduced. As a result, the influence of carbon content and deposition temperature upon material metastability has been worked out. Moreover, although hydrogen diffusion is involved in relaxation of a-CSiGe:H, it has been proved that this is not the rate-limiting step of the process.