The Property of ITO Produced by Optical Thin Film Coating for Solar Cell

We studied the crystal quality and optical properties of ITO produced with optical thin film coatings to replace conventional metal electrodes as electrodes for III-V solar cells. ITO films were grown on glass, GaAs and silicon substrate. ITO is a polycrystalline with predominant (222) crystalline plane. A smooth surface with protruding nano-crystallite was observed. The light transmittance of ITO has a strong relationship with thickness and annealing temperature. The transmittance was obviously enhanced after being annealed at 500 °C. With the thickness increase, the transmittance decreases in total. The band gap of the ITO film was estimated 3.8 eV by extrapolating the linear part of the Tauc plot curves to intercept the energy axis. The refractive index n of ITO film is was measured. The reflectivity is greatly influenced by the thickness of ITO.