Regensburg 2010 – wissenschaftliches Programm
HL 60.17: Poster
Donnerstag, 25. März 2010, 18:00–20:00, Poster D1
Temperature dependence of the optical energy gap in the absorption edge of the ZrSxSe2−x layered semiconductor — •Mohamed Moustafa, Anke Wasnick, Christoph Janowitz, and Recardo Manzke — Institut für Physik, Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489 Berlin, Germany
The energy band gap values Eg of single crystals of layered transition metal dichalcogenide semiconductors of ZrSxSe2−x (where 0 x 2) have been determined from the optical absorption measurements at different temperatures. The samples were prepared by the chemical vapour transport technique and characterized with help of different methods such as LEED and EDX. The band gap values showed an approximate linear dependence with the composition parameter x. The temperature dependence of Eg is presented and compared to the semi-empirical model proposed by Mannogian and Woolley . Additionally, the observed exponential behaviour of the absorption coefficient tail near the fundamental edge is analysed and interpreted based on the Urbach rule .
 A. Mannogian and J. C. Woolley, Can. J. Phys. 62, 285 (1984)
 F. Urbach, Phys. Rev. 92, 1324 (1953)