Document Details Document Type : Article In Journal  Document Title : Electrical and optical properties of a-SexTe100-x thin films Electrical and optical properties of a-SexTe100-x thin films   Subject : physics  Document Language : English  Abstract : The dc electrical conductivity of as deposited thin films of a-SexTe100-x (x = 3, 6, 9 and 12) is measured as a function of temperature range from 298 to 383 K. It is observed that the dc conductivity increases exponentially with the increase in temperature in this glassy system. The value of activation energy calculated from the slope of In sigma(dc) vs. 1000/T plot, is found to decrease on incorporation of dopant (Se) content in the Te system. On the basis of pre-exponetial factor (sigma(o)), it is suggested that the conduction is due to thermally assisted tunneling of the carriers in the localized states near the band edges. The optical absorption measurements show an indirect optical band gap in this system and it decreases on increasing Se concentration. The optical constants (extinction coefficient (k) and refractive index (n)) do change significantly with the photon energy and also with the dopant Se concentration. The decrease in optical band gap may be due to the decrease in activation energy in the present system. It is also found that the real and imaginary parts of dielectric constants show a significant change with the photon energy as well as with the dopant concentration. With large absorption coefficients and compositional dependence of optical band gap and optical constants (n and k), these materials may be suitable for optical disk applications. (C) 2011 Elsevier Ltd. All rights reserved.  ISSN : 0030-3992  Journal Name : OPTICS AND LASER TECHNOLOGY  Volume : 44  Issue Number : 1  Publishing Year : 1433 AH 2012 AD  Article Type : Article  Added Date : Tuesday, July 25, 2017  Researchers Researcher Name (Arabic) Researcher Name (English) Researcher Type Dr Grade Email Zishan H (Khan (Khan, Zishan H Investigator Doctorate   Numan Salah Salah, Numan Researcher Doctorate   Sami Habib Habib, Sami Researcher Doctorate   A.A Al-Ghamdi, Al-Ghamdi, A.A Researcher Doctorate   Shamshad A. Khan Khan, Shamshad A Researcher Doctorate   Files File Name Type Description  42259.pdf pdf   Back To Researches Page