Photon assisted hopping conduction mechanism in Tl2SSe crystals

Abstract

In this article, the powder X-ray diffraction data and the dark and the photo-excited electrical conduction parameters of Tl2SSe crystal are reported. The dark and photon excited electrical conduction in the tetragonal crystal are found to be dominated by thermionic emission assisted variable range hopping conduction (VRH). The dark Molt's VRH parameters representing by the degree of disorder (T), the density of localized states near the Fermi level (N(E-F)), the average hopping range (R) and average hopping energy (W) exhibited wide tunability via incremental photon intensity. Particularly, while the dark values of T-0, W and R significantly decreased from 2.32x 10(8) to 1.52x10(5) K, 114 to 18.25 meV and from 66.15 to 10.58 A, respectively, the values of N(E-F) increased from 7.23 x 10(18) to 1.10 x 10(22) cm(-3)/eV when the crystal was photo-excited with a 53.6 mW/cm(2) light intensity. These variations in the hopping parameters via photon excitations are promisig for using the crystal in the fabrication of well controlled, widely tunable, low energy consuming and highly efficient electronic devices. (C) 2014 Elsevier B.V. All rights reserved