Preparation and characterization of n-type microcrystalline hydrogenated silicon oxide films

We have developed n-type microcrystalline hydrogenated silicon oxide (n-μc-SiO:H) thin films by the radio frequency plasma enhanced chemical vapour deposition (RF-PECVD, 13.56 MHz) method having suitable characteristics for use in the fabrication of single or multijunction amorphous silicon (a-Si) solar cells. The films have been characterized in detail for the study of structural and optoelectronic properties. Transmission electron microscopy, Raman spectroscopy, x-ray diffraction, Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy have been used for the structural studies. The dependence of the structure and optoelectronic properties of n-μc-SiO : H films on the various deposition parameters such as hydrogen dilution, chamber pressure, RF-power density etc have also been studied. Comparison of the properties between n-μc-SiO:H and n-μc-Si:H films have been studied, too, which shows that the former has higher optical gap (2.17 eV) and lower activation energy (0.015 eV) with similar electrical conductivity (12.08 S cm-1). (author)