Energy structure and micromechanism of photo-electromotive force effect in V-doped CdTe crystals

For the first time photo‐electromotive force (photo‐EMF) measurements were carried out for CdTe crystals doped with V atoms as a result of the photogeneration of carriers from deep impurity centers to the conduction band. Tilted geometry was applied that allowed two‐dimensional monitoring of the vi‐ bration source. The CdTe:V crystals were excited by a He–Ne laser with a wavelength of 1.15 μm (ħω = 1.08 eV) and P = 2 mW. The mechanism of the appearance of the holographic current in the CdTe:V crystals taking into account real defect structure was proposed. The frequency dependence of the ac photo‐EMF (holographic) current for the CdTe:V crystals was measured. It was shown that a low cut‐off frequency for a laser intensity I = 0.2 mW/mm2 equals 6.0 kHz, which corresponds to a response time of 26 μs. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)