25 research outputs found
Electronic structure of carbon-free silicon oxynitride films grown using an organic precursor hexamethyl-disilazane
Silicon oxynitride films are grown by plasma-enhanced chemical vapour deposition on single-crystal Si(100) and textured Si solar cells, using a safe organic precursor, hexamethyl-disilazane. Using the Lucovsky-Phillips criterion of bond coordination constraints, we grow high-quality thin (~20 Å) and thick (up to 2700 Å) films which are carbon free (<1.0{%}) as characterized by x-ray photoemission spectroscopy (XPS) and Auger electron spectroscopy depth profiles. Core-level and valence band XPS is used to conclusively identify oxynitride bonding and band gap reduction in SiOxNy. For a λ/4 'blue' anti-reflection coating on the solar cells with uniform thickness (870± 15 Å) and composition (SiO1.6± 0.1N0.3± 0.05), an efficiency (AM 1) increase of 1{%} is obtained
Plasma polymerization using a constricted anode plasma source
This paper investigates plasma polymerization of hexamethyl disiloxane (HMDSO) using a constricted anode plasma source (CAPS). The CAPS uses a new electrode configuration i.e. a small anode surrounded by a large cathode, which allows a plasma to be sustained at low pressure of 1× 10-3 mbar. Using CAPS, polymerization of HMDSO in the presence of oxygen was carried out, which resulted in the formation of pinhole free glass-like coating on aluminum substrates. The coating was analysed using X-ray photoelectron spectroscopy, which confirmed the presence of the Si-O-C and the SiOx. Near the coating surface more oxygen was obtained than in the bulk of the coating. With the increase in the deposition temperature, the carbon content in the coating decreased. The corrosion resistance also increased with the increase in deposition temperature. The results establish that the new electrode configuration used in the present investigation can produce good quality coatings by polymerization of a precursor