Free Carrier Absorption in CdS_xSe_1−x Single Crystals

Abstract

Free Carrier Absorption in CdS,Se,,, Single Crystals BY M. P. LISITSA (a), Z. A. DEMIDENKO (b), V. N. MALINKO (a), E. V. PIDLISNYI (a), M. YA. VALAKH (a), and N. I. VITRIKHOVSKII (a) Free electron absorption in single crystals of CdS and CdSe, as well as in CdS,Sel-, solid solutions ( r = 0.80, 0.58, 0.43, 0.36, 0.31, 0.21), has been investigated at Hall concentrations N = 2 x 10l6 to 2 x loL9 cm-3 in the temperature interval T = 80 to 450 OK. For all the saniples investigated, absorption coefficients K -A", where n = f ( N , T ) , and a mixed mechanism of scattering by optical phonons and charged impurities is found, whereas for N of the order of 1016 ~r n -~ scattering occurs practically only by optical phonons. An interpretation of the wavelength and concentration dependences of the measured absorption Coefficients is given. ~CC.TIe;[OBaHO IIOrJIOIIJeHHe CBeTa C B O f i O~H b I M M 3JIeKTpOHaMH B MVHOKPHCTaJIJIaX CdS, Case, TaKiKe €3 CMeJlIaHHblX MOHOKpMcTaJIJIaX CdS,Sel-, (X = 0,s; 0,58; 0,43; 0,%; 0,31 II 0,zl) IIpH XOJIJIOBCKIIX KOHUeHTPaUHRX = 2 X CM-3 Ro 2 X loi9 C K 3 B TeMIIepaTypHOM MHTepBaJIe T = 80 K O 450 "H. AJIR BCeX HccJIeno-BaHHbIX 06' beKTOB K -An, n = f(Lv, T ) , MMeeT MeCTO CMeIUaHHbIB MeXaHM3M CM-3 -IIpaHTLZ9eCHH TOJlhIEO Iia OIITPI9eCKHX $OHOHaX. AaHa TpaKTOBKa CIIelrTpaJILHOih PI IIOHUeHTpaQMOIiHOih 3aBHCIIMOcTCL? PI3MepeHIIbIX KO3@@IIuHeHTVB a paccemm Ha OrITwIecmix QomHax PI a a p~r n e~~m x IqmMecRx, n p~ M nopcrnrca normii~eHkI~.

Infrared absorption spectra of Cd0.2Hg0.8Te crystals

“…I n this case the parameter r must be a function of wavelength, concentration of free carriers, and temperature [3]. Thus, scattering mechanisms can be determined only by a quantitative comparison of experimental and calculated absorption spectra.…”