Effect of Substrate Temperature on Properties of Glow-Discharged Hydrogenated Amorphous Silicon

The substrate temperature dependence of the transport and photoelectric properties of glow-discharged hydrogenated amorphous silicon films has been studied in connection with the morphological heterogeneity in the films. The electron drift mobility at room temperature determined by the time-of-flight method increases exponentially as the substrate temperature is raised, and is possibly associated with the formation of a percolation path through the growth of small quasi-crystalline zones. In contrast with the exponential increase in the electron mobility, the lifetime, or the deep-level trapping time, of electrons shows a maximum at a substrate temperature of 200°C, in parallel with the ESR spin density and tail-to-tail luminescence intensity.