OPTICAL PARAMETERS OF THERMALLY EVAPORATED CdTe THIN FILMS

摘要

Cadmium telluride is an interesting material for the use in solar cells as an absorber layer. The optimization of the optical parameters of this material is an important step on the way to produce high efficiency solar cells. In this work polycrystalline cadmium telluride (CdTe) thin films with approximate values of film thickness (1 μm) are prepared on glass substrates at ambient temperature by thermal evaporation. Scanning electron microscopy (SEM) revealed that the films are polycrystalline. The transmittance of the films is measured at room temperature in the wavelength range (400-1100 nm) and used to deduce the optical parameters. The extinction coefficient (k), refractive index (n), the real and imaginary parts of the dielectric constant (ε_r and ε_i ) are investigated.