Spectroscopic characterization of photorefractive CdTe : Ge

We report on the photoabsorption, magnetic circular dichroism (MCD) and ele ctron paramagnetic resonance (EPR) of Ge-doped CdTe. Strong photoinduced ab sorption changes have been detected for two samples at ambient and low temp eratures (down to 4.3 K). They reveal the existence of four absorption band s around 0.94, 1.10, 1.22 and 1.36 eV at 4.3 K. MCD experiments at: 1.4 K a llowed the tagging of different paramagnetic defects to the two bands at lo wer energies. EPR demonstrated that one of them is Ge-Cd(+). We propose tha t the second one is an isolated or Ge-related A-centre. A diagram showing t he various transport processes is given. (C) 1999 Elsevier Science B.V. All rights reserved.