Turkish Journal of Physics
DOI
-
Abstract
Dependence of the absorption coefficient on the photon energy and temperature near the fundamental absorption edge was measured for layered single crystal TlGaS_{2}. The exponentially increasing absorption tail was explained as an Urbach-Martienssen's (U-M's) tail for TlGaS_{2} samples in the 10-340 K temperature range. The characteristic Urbach's parameters such as steepness parameter [\sigma (T)] and Urbach's energy [(E_{u} = k_{B} T / \sigma )] were determined. Analyzing the temperature dependence of these parameters based on the general models, which takes into account the possible role of several different types of disorder, we conclude that the absorption process in the fundamental absorption edge for TlGaS_{2} is the result of the superposition of at least two different mechanisms; one is related to the phonon induced microfields and the other results from structural and thermal disorders.
Keywords
Optical characterization; Urbach rule; layered semiconductors; TlGaS_{2}.
First Page
543
Last Page
550
Recommended Citation
ABAY, BAHATTİN; GÜDER, HÜSNÜ SALİH; EFEOĞLU, HASAN; and YOĞURTÇU, YAHYA KEMAL (2001) "Urbach-Martienssen's tail in layered ternary semiconductor TlGaS_{2}," Turkish Journal of Physics: Vol. 25: No. 6, Article 8. Available at: https://journals.tubitak.gov.tr/physics/vol25/iss6/8
