<title>Studies of deep trapping levels in undoped and Sn-doped Cd<formula><inf><roman>1-x</roman></inf></formula>Zn<formula><inf><roman>x</roman></inf></formula>Te by thermoelectric effect spectroscopy and thermally stimulated current</title>

Abstract

Thermoelectric effect spectroscopy (TEES) and thermally stimulated current (TSC) were used to study the deep trapping levels in undoped and Sn doped Cd1-xZnxTe crystals. Temperature maximum, varying heating rate and initial rise methods were used to extract activation energies and trapping cross sections of the deep trapping levels in the samples. The concentration of deep levels was estimated from the resistivity data using Neumark model. The pure sample had deep trapping levels with ionization energies of EV + 0.73 eV and EV + 0.74 eV. The concentration of the deep levels was estimated at 500 ppb. These deep levels were associated with intrinsic defects due to Cd vacancies and Te antisites. In the Sn doped samples deep levels at EV + 0.34 eV, EV + 0.55 eV and EV + 0.73 eV were observed. The level at EV + 0.55 eV was associated with Sn, while the EV + 0.34 eV and EV + 0.73 eV levels were associated with Cd vacancies. The concentration of these levels was estimated a 10000 ppb. The pulse height measurements on these samples indicated that Sn doping did not improve the detector performance.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.