Cadmium zinc telluride (CdZnTe) compound semiconductor crystal has been shown to be one of the most promising materials for X-ray and γ-ray detectors [1]. This material gained interest due to its ability to work as room temperature radiation detector. However, the high yield production of quality crystals is still a challenge both for scientists and engineers. It is due to presence of defects in grown crystals: Te inclusions, crystal twins, dislocations, grain boundaries and other defects. Several researchers have shown a possibility to improve crystal quality by using CO2 laser processing [2]. The disadvantages of this method are long processing time - about 100 h and damage of the crystal as a result of laser irradiation. We have studied the influence of infrared laser radiation on CdZnTe crystal electrical properties and radiation detector parameters. CdZnTe has low optical absorption coefficient in infrared region of spectra. Therefore, laser radiation is absorbed mostly by Te inclusion and point defects. II. EXPERIMENTS AND DISCUSSION In our experiments we have used Cd1-xZnxTe x= 0.1 single crystals grown by High-Pressure Vertical Zone Melting method. Nd:YAG laser with the following parameters: wavelength λ = 1064 nm, pulse duration τ = 3 ns, power P = 1.0 MW was used. Irradiation of the crystals was carried out with intensity I=5.0 MW/cm2 and maximum number of the laser pulses 28.8×104. To characterize the change of CdZnTe crystal lattice quality after irradiation by laser, infrared transmission spectroscopy (FTIR) was used.Experiments were carried out at room temperature, in atmospheric pressure and humidity 60%. FTIR spectra of non irradiated and irradiated samples by the laser with deferentradiation doses are shown in figure 1. After reaching 7.2×104 laser pulses the transition of the crystal is decreasing, which can be explained by damage of crystalline lattice due to prolonged exposure to laser radiation. Current voltage (I-V) characteristic measurements showed that sample resistivity is rising after irradiation with 7.2×104 laser pulses by 45%, as shown in figure 2. After reaching specific number of pulses, saturation effect can be observed. It means that CdZnTe sample resistivity does not change significantly with increasing of number of pulses.Increase of CdZnTe samples electrical resistivity is explained by presence of gradient of temperature around Te inclusions [3]. Gradient of temperature arise in the crystal due to absorption of the laser radiation by Te inclusions. As a result small inclusions and interstitial impurities drift to the maximum of temperature, towards the biggest Te inclusions, where they dissolve and precipitate [4]. III. CONCLUSIONS Infrared Nd:YAG laser radiation reduces CdZnTe sample leakage current by 30% and increase transparency in infrared region of spectra by ~2% due to precipitation of impurities . IV. REFERENCES [1] T. E. Schlesinger, J. E. Toney, H. Yoon, YE. Lee, B. A. Brunett, L. Franks, R. B. James, “Cadmium zink telluride and its use as nuclear radiation detector material”, Materials Science and Engineering, Vol. 32, 2001, pp. 103-189. [2] M. Meier, M. J. Harrison, S. Spalsbury, D. S. McGregor, “Laser-induced thermomigration of Te precipitates in CdZnTe crystals”, Journal of Crystal Growth, Vol. 311, 2009, pp. 4247. [3] A. Medvid’, “Redistribution of the Point Defects in Crystalline Lattice of Semiconductor in Nonhomogeneous Temperature Field”, Defects and Diffusion Forum, 2002, Vols. 210- 212, pp. 89-101. Acknowledgment: This work has been supported by the European Social Fund within the project «Support for the implementation of doctoral studies at Riga Technical University».