On Correlation between Visible?Near-Infrared Transmittance Spectra and Structural Properties of Plasma Deposited Nanocrystalline Silicon Thin Films

摘要

Visible?near-infrared transmittance (T) spectra is correlated with the structural properties of hydrogenated nanocrystalline silicon (nc-Si:H) thin films, produced by plasma enhanced CVD (PECVD) under various RF power densities (100?444 mW/cm~2), various substrate temperatures (80?200 °C), at different regions of the PECVD electrode (center/edge). It is found that for the highly crystalline films there is downward deviation of maximum T envelope curve (T_M) from the glass substrate T (T_(substrate)) in 650?900 nm region, and it is linearly proportional to grazing angle XRD (GAXRD) (111) peak height. Field emission SEM (FE-SEM) surface reveals conglomerates for these films. T_M≈T_substrate for the films with low GAXRD (111) peak height or fully amorphous samples, which have partially or fully smooth FE-SEM film surface, respectively. The effect of each film structural property (surface roughness, columns, incubation layer, etc.) on the observed deviation of T_M from T_(substrate) is considered.