Electrical studies on bulk Se sub(96)Sn sub(4) semiconducting glass before and after gamma irradiation

• Published in: The Journal of physics and chemistry of solids Vol. 71; no. 11; pp. 1534 - 1539
• Main Authors: Al-Bati, Sameer N, Lafi, Omar A, Imran, Mousa MA, Shaderma, Moh'd M
• Format: Journal Article
• Language: English
• Published: 01.11.2010
• Subjects: Activation energy; Density; Electric fields; Gamma irradiation; Gamma rays; Glass; Irradiation; Ohmic
• ISSN: 0022-3697
• DOI: 10.1016/j.jpcs.2010.07.023

Bulk Se sub(96)Sn sub(4) chalcogenide glass was prepared by melt quenching technique and irradiated by different doses of 4, 8, 12, 24 and 33 kGy using super(60)Co gamma emitter. I-V characteristics were obtained for this glass, before and after gamma irradiation, in the temperature range 200-300 K. Ohmic behavior was observed at low electric fields (<=1x10 super(4) V/m), while at higher fields, a deviation from ohmic towards non-ohmic behavior was observed. The plots of ln(I/V) vs. V were found to be straight lines and the slopes of these lines decrease linearly with temperature indicating the presence of SCLC. In the temperature range of measurements, the dependence of DC conductivity on temperature at low electric field shows two types of conduction channels, one in high temperature range 270-300 K and the other at low temperature range 200-270 K. Analysis of the experimental data shows that the conductivity at room temperature decreases with increase in irradiation dose. This is attributed to rupturing of SnSe sub(4/2) structural units, upon irradiation, and rebuilt of Se atoms between Se chains. This redistribution of bonds, induced by gamma irradiation, is responsible for the corresponding increase in the activation energy. The obtained values of the activation energy indicate that the conduction occurs due to thermally assisted charge carriers movement in the band tail of localized states. However, in the low temperature range, results obtained from Mott's variable range hopping (VRH) model reveal that the density of localized states has its maximum value at a gamma dose of 12 kGy, while the disorder parameter T sub()o hopping distance R sub()hopand hopping energy W have their minimum value at this particular dose.