Photoluminescence of iodine-doped ZnTe homoepitaxial layer grown by metalorganic vapor phase epitaxy

Photoluminescence (PL) properties of I-doped ZnTe homoepitaxial layers grown by atmospheric pressure metalorganic vapor phase epitaxy have been investigated as a function of n-butyliodide (n-BuI) transport rate. The PL spectrum changed drastically even when a low dopant transport rate was used. A structured emission band at 2.22 eV was detected predominantly at low n-BuI transport rates, whereas a structureless broad emission band at around 2.17 eV or less dominates the PL spectrum at high n-BuI transport rates. PL spectra of I-doped ZnTe layers were analyzed at varying excitation power and temperature. These luminescence bands are due to donor-acceptor pair recombination, and may be ascribed to complexes consisting of Zn vacancies and I on Te sites close to donors. (C) 2003 American Institute of Physics.