Effect of Preparation Conditions on the Fundamental Absorption Edge of Y2O3 Thin Films
The fundamental absorption edge of Y2O3 thin fi lms obtained by discrete evaporation and high-frequency (HF) onplasma sputtering in various atmospheres was studied using optical spectroscopy. It was ascertained that the optical bandgap Eg increased from 5.65 eV for Y2O3 fi lms obtained by discrete evaporation to 5.77 eV for fi lms obtained by HF sputtering in Ar to 5.90 eV for fi lms obtained by HF sputtering in O2. The effective reduced mass of free charge carriers was estimated. It was found that the concentration of free charge carriers in Y2O3 fi lms obtained by ionplasma sputtering in Ar with 50% O2 was N = 1.34·1017 cm–3 whereas sputtering in 100% O2 gave N = 1.38·1018 cm–3, which was typical of degenerate semiconductors. It was shown that the shift of the fundamental absorption edge in Y2O3 thin fi lms after addition of O2 to the sputtering atmosphere was most likely caused by the Burstein–Moss effect.
Keywordsyttrium oxide thin fi lm fundamental absorption edge
Unable to display preview. Download preview PDF.
- 4.M. E. Globus and B. V. Grinev, Inorganic Scintillators. New and Traditional Materials [in Russian], Akta, Kharkov (2001).Google Scholar
- 11.O. M. Bordun, I. O. Bordun, and I. I. Kukharskii, Zh. Prikl. Spektrosk., 79, No. 6, 984–989 (2012) [O. M. Bordun, I. O. Bordun, and I. Yo. Kukharskyy, J. Appl. Spectrosc., 79, No. 6, 982–987 (2012)].Google Scholar
- 12.I. M. Tsidil′kovskii, Band Structure of Semiconductors [in Russian], Nauka, Moscow (1978).Google Scholar
- 13.J. I. Pankove, Optical Processes in Semiconductors [in Russian], Mir, Moscow (1973).Google Scholar
- 15.G. Betz and G. K. Wehner, in: Sputtering by Particle Bombardment II, R. Berisch (ed.), Topics in Applied Physics, Vol. 52, Springer, New York (1983) [Russian translation, pp. 24–133].Google Scholar
- 19.H. L. Hartnagel, A. L. Dawar, A. K. Jain, and C. Jagadish, Semiconducting Transparent Thin Films, Institute of Physics Publ., Bristol (1995), pp. 4–7.Google Scholar
- 20.T. P. McLean, Prog. Semicond., 5, 53–58 (1960).Google Scholar
- 21.B. F. Ormont, in: Introduction to Physical Chemistry and Semiconductor Crystal Chemistry [in Russian], VysshayaShkola, Moscow (1973).Google Scholar