In the other hand in series
We have deposited and characterized pm-Si:H and μc-Si:H thin films by PECVD at low substrate temperature 200 °C. We have found that A 77636 the deposition pressure and the RF power density have an important influence on the structural, optical and electrical characteristics of the films.
From AFM characterization we found that large deposition pressure (larger than the used for a-Si:H) results in an increment on the Ra values of the films surface, which is associated with the formation of nanocrystals in the amorphous matrix.
From Raman characterization we corroborated the nature of the μc-Si:H films, where crystalline fractions as large as 67.9% were calculated; as well from UV–Visible spectroscopy we confirmed the polymorphous nature of the films, since Eopt values in the range of 1.83–1.94 eV were obtained, which are similar to these reported in literature for this kind of films.
From electrical characterization we extracted Ea and σRT of the different films, for μc-Si:H we found optimal conditions that provide large crystalline fraction and large σRT, while in the other hand, high σRT and Ea values were obtained in the pm-Si:H films, which in comparison with works reported in literature are similar or even larger. The change of conductivity from dark to AM 1.5 illumination, in about 6 orders of magnitude in the optimized pm-Si:H films makes this material very suitable for solar cells applications.