A detailed characterization of the impurity centers involved in the ph
otoluminescence (PL) of p-type CdTe doped with arsenic (As) and antimo
ny (Sb) has been performed. The PL spectrum has been measured from 1.3
5 eV up to the band edge and as a function of temperature (4.2 up to 3
0 K). In addition to the familiar broad PL line centered at 1.45 eV an
d present in undoped and doped materials, the doped samples exhibit a
new band near 1.54 eV showing a fine structure composed of two peaks w
hose intensities vary with temperature. The observed longitudinal opti
cal (LO) phonon replicas associated with the zero-phonon lines, at 1.4
5 eV and 1.54 eV, respectively, are characterized by a Huang-Rhys fact
or S=1.3+/-0.1 and S=0.30+0.02. The various electron-hole recombinatio
n processes are explained by means of a simple analytic model correlat
ing the position of the zero-phonon lines to the relative intensities
of the phonon side bands. The model accounts for the chemical shift of
the defect centers and describes the effect of the charge carrier LO-
phonon interaction in the framework of the adiabatic approximation wit
hin the envelope function approach. Comparison between theory and expe
riment leads to the following values for the: effective Bohr radii: a(
As)=(10.6+/-0.1) Angstrom, a(Sb)=(10.3+/-0.1) Angstrom, and ionization
energies: E(As)=(58+/-2) meV, E(Sb)=(61+/-2) meV. It also leads to co
nclude to the presence of native shallow donors with binding energy E(
D)=(13+/-2) meV and of deeper native acceptor complexes with effective
Bohr radius a(A)=(6.1+/-0.1) Angstrom and ionization energy E(A)=(157
+/-2) meV. (C) 1995 American Institute of Physics.