Akademik Veri Yönetim Sistemi
Chinese Journal of Physics, cilt.43, sa.4, ss.856-866, 2005 (SCI-Expanded)
The InSe:Er single crystals used for the characterization have been grown using the Stockbarger method. The grown InSe:Er single crystal ingots are 12 mm in diameter and about 80 mm in length. The ingots had no cracks or voids on their surface. The absorption measurements were carried out for the U = 0 and U = 40 V states of an InSe:Er sample in the temperature range of 10-320 K. The binding energies for the U = 0 and U = 40 V states were calculated to be (4.25 +/- 0.04) and (3.25 +/- 0.04) meV, respectively. At 10 K, the direct band gaps of the U = 0 and U = 40 V states of InSe:Er were calculated to be 1.322 and 1.315 eV and for the indirect band gaps, 1.313 and 1.308 eV, respectively. The steepness parameters and Urbach energy for the U = 0 V and U = 40 V states in the InSe:Er sample increased with the sample temperature in the 10-320 K range. The influence of an electric field on the absorption edge of InSe:Er was investigated as a function of,the temperature. A large sift in the absorption edge towards longer wavelengths was observed in the layered InSe:Er single crystal. The applied electric field caused a shift and a decrease of intensity in the absorption spectra and an increase in the Urbach energy and steepness parameters. The shift of the absorption edge can be explained on the basis of the FKE or thermal heating of the sample under the electric field. The effective mass (m*) of InSe:Er was calculated to be 0.424 m(0).