A Comparative Study of SiO_2:TiO_2 Composite and SiO_2 Film by Sol-Gel Method for Solar Cell Application

摘要

Thin films of SiO_2 and SiO_2-TiO_2 composite sol were spin coated on textured monocrystalline silicon wafer and clean glass using Tetraethyl orthosilicate (TEOS) and Titanium tetraisopropoxide (TTIP) as main precursors. For further improvement of the films quality, DMF (dimethylformamide) was added into the solutions to reduce the cracks of the film. The average reflectance of the composite and oxide films was 8.8 and 6.81%, whereas textured monocrystalline silicon (without any coating) wafer having a reflectance of 13.20%. Both the films were annealed at different temperatures ranging from 400 to 900 °C with an interval of 100 °C. After annealing minority carrier lifetime significantly changes from 3.26 to 40.5 μs at 800 °C for oxide film and for composite it was 3.51-45.29 μs at 800 °C. These results show that both the films can be used as an ARC (anti-reflection coating) as well as a passivation layer for solar cell application.