Silicon Surface Passivation by Laser Processing a Sol–Gel TiOx Thin Film
Silicon surface passivation is highly important for solar cells and other optoelectronic devices. In order to achieve a high-performance, low-cost, room-temperature, and nonvacuum surface passivation, we investigated laser processing of sol–gel TiOx films on n-type semiconductor silicon. We achieved an effective lifetime of 1.11 ms and surface recombination velocity SRV = 6.25 cm/s using 60 nm thin TiOx film and laser fluence value near the silicon melting point (1.19 J/cm2). Through structural and electrical analysis, we provide the mechanism of laser processing for achieving excellent surface passivation. We found that laser processing can induce chemical passivation in addition to the intrinsic field effect passivation and can accelerate the sol–gel reaction while maintaining a high-purity TiOx film. Moreover, the optical reflection and refractive index measurements were carried out, and results show that our laser-processed TiOx films can function as antireflection layer and provide excellent passivat...