Thin Solid Films, Vol.451-52, 184-188, 2004
Non-equilibrium procesess in CdTe material
Studies of the lifetime of non-equilibrium charge carriers and their recombination mechanisms are particularly important to the design of photovoltaic devices. In this present work, photoconductivity properties of CdTe crystals are investigated in a wide temperature range (T=400-10 K) by the photo-induced current transient spectroscopy (PICTS) method. The bulk Bridgman CdTe samples was studied in the pulsed activation domain. Following these measurements, the value of deep (E-A=200 meV) recombination level and shallow trap levels (E-B=1 meV) were determined. Level E, result from structural defects of the Cd sublattice. In the low temperature region (T<40 K), the trapping levels contribute largely to the photoconductivity process. The photoresponse also points out to the asymmetry of the rise and relaxation times, which is caused by the trapping levels and macrodefects. (C) 2003 Elsevier B.V. All rights reserved.