Photoluminescence study of γ-irradiation effect on the defect structure in Ge-doped CdTe single crystals

• Published in: Physica status solidi. C Vol. 11; no. 9-10; pp. 1510 - 1514
• Main Authors: Nasieka, Iu, Rashkovetskyi, L., Boyko, M., Strelchuk, V., Tsybrii, Z., Danilchenko, B., Shcherbak, L.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.09.2014; WILEY‐VCH Verlag
• Subjects: Bands; Cadmium tellurides; CdTe crystals; Crystal defects; Emission; Ge-doping; Irradiation; low-temperature photoluminescence; Luminescence; Photoluminescence; Single crystals; γ-irradiation
• ISSN: 1862-6351; 1610-1642
• DOI: 10.1002/pssc.201300571

An effect of γ‐irradiation in the dose range 10‐500 kGy on the defect structure of Ge‐doped CdTe single crystals (CdTe:Ge) was investigated via the method of low‐temperature photoluminescence. It was obtained that γ‐irradiation in mentioned above dose range leads to the substantial decreasing of intensities of excitonic emission bands – D0X, A0X, VDX and increase in the intensities of impurity‐related emission bands – eA1,eA2, DA. It was shown that such changes in the luminescence can be explained by radiation‐stimulated redistribution of luminescence centers between recombination channels. The latter includes vacancy‐type defects filling by Ge dopant atoms which leads to the improving of the crystalline perfection of irradiated CdTe:Ge crystals. Mentioned material quality increasing was confirmed analysing the electron‐LO‐phonon coupling in irradiated crystals which was characterized via the Huang‐Rhys factor for corresponding luminescence bands. For the verification of the assumption about radiation‐stimulated compensation of native defects the resonant Raman measurements also were carried out. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)