DETERMINATION OF CUTOFF WAVE-NUMBER AND C OMPOSITION FOR HGCDTE USINGTHE PEAK OF THE REFLECTANCE SPECTRUM IN THE INTRINSIC REGION

Transmittance and reflectance spectra measurements were carried out. f or a series of HgCdTe samples by FTIR spectrometer. Transmittance curv e was used to determine the composition of each sample. An obvious pea k was observed in the reflectance spectrum. By considering the dispers ion of the absorption coefficient of direct band gap samples and K-K r elation, theoretical analysis show this peak appears in the region of E-g < h omega(m) < 2E(g). Through comparison of the wavenumber of the peak in the reflectance spectrum with the cut-off wavenumber, the dire ct proportion relationship of them was obtained and the proportion coe fficient is 1.092.