Abstract
Thin CdTe films have been grown by vacuum evaporation. Optical transmission spectra as a function of temperature have been analysed by Kramers-Kronig analysis technique. This yielded accurate refractive index values in the region of the optical absorption edge. The band gap energy was determined as the position of the maximum derivative of the imaginary part of the refractive index. The resulting thin-film band gap was: Eg(eV)=1.626-3.25*10-4 T (T in K), valid from 123 to 623 K. This new application of the Kramers-Kronig analysis is shown to be very powerful and reliable.