Edge Absorption of thin Films –Ga2O3

O.M. Bordun; B.O. Bordun; V.B. Lushchanets; I.Yo. Kukharskyy

doi:10.15330/pcss.16.2.302-306

Authors

O.M. Bordun Ivan Franko National University of Lviv
B.O. Bordun Ivan Franko National University of Lviv
V.B. Lushchanets Ivan Franko National University of Lviv
I.Yo. Kukharskyy Ivan Franko National University of Lviv

DOI:

https://doi.org/10.15330/pcss.16.2.302-306

Keywords:

gallium oxide, thin films, fundamental absorption edge

Abstract

Fundamental absorption edge of b–Ga₂O₃ thin films, obtained by radio-frequency ion-plasmous sputtering, was investigated, using the method of optical spectroscopy. It was ascertained that the optical band gap E_g increases from 4.60 to 4.65 eV after the heat treatment films in argon atmosphere and to 5.20 eV after the reduction of annealed films in a hydrogen atmosphere. Consolidated effective mass of free charge carriers in b–Ga₂O₃ films after annealing and after reduction in hydrogen was estimated. It was found that the concentration of charge carriers after heat treatment in argon atmosphere is 7.30´10¹⁷ cm^–3 and after reduction in hydrogen, is 2.62´10¹⁹ cm^–3, which is typical for degenerated semiconductors. It was shown that the shift of fundamental absorption edge in thin films b–Ga₂O₃ after reduction in hydrogen is caused by Burstein-Moss effect.

References

[1] Z. Liu, T. Yamazaki, Y. Shen, T. Kikuta, N. Nakatani, Y. Li, Sensors and Actuators B 129 (2), 666 (2008).
[2] J.-T. Yan, C.-T. Lee, Sensors and Actuators B 143 (1), 192 (2009).
[3] M. Passlack, M. Hong, E. F. Schubert, J. R. Kwo, J. P. Mannaerts, S. N. G. Chu, N. Moriya, F. A. Thiel, Appl. Phys. Lett. 66 (5), 625 (1995) .
[4] J.-G. Zhao, Z.-X. Zhang, Z.-W. Ma, H.-G. Duan, X.-S. Guo, E.-Q. Xie, Chinese Phys. Lett. 25 (10), 3787 (2008).
[5] K. Shimamura, E. G. Víllora, T. Ujiie, K. Aoki, Appl. Phys. Lett. 92 (20), 201914 (2008).
[6] P. Wellenius, A. Suresh, J. V. Foreman, H. O. Everitt, J. F. Muth, Mater. Sci. Eng. B 146, 252 (2008).
[7] T. Minami, T. Shirai, T. Nakatani, T. Miyata, Jpn. J. Appl. Phys. 39 (6A), L524 (2000).
[8] T. Miyata, T. Nakatani, T. Minami, Thin Sol. Films 373 (1–2), 145 (2000).
[9] A. Ortiz, J. C. Alonso, E. Andrade, C. Urbiola, J. Electrochem. Soc. 148 (2), F26 (2001).
[10] Z. Ji, J. Du, J. Fan, W. Wang, Opt. Mater. 28 (4), 415 (2006).
[11] M. F. Al-Kuhaili, S. M. A. Durrani, E. E. Khawaja, Appl. Phys. Lett. 83 (22), 4533 (2003).
[12] H. W. Kim, N. H. Kim, Appl. Surf. Sci. 230 (1–4), 301 (2004).
[13] V. M. Kalygina, A. N. Zarubin, V. A. Novikov, Y. S. Petrova, O. P. Tolbanov, A. V. Tyazhev, S. Y. Tsupyy, T. M. Yaskevich, FTP 47 (5),
598 (2013).
[14] R. Swanepoel, J. Phys. E: Sci. Instrum. 16, 1214 (1983).
[15] A. S. Valeev, Opt. and Spectr. 15 (4), 500 (1963).
[16] I.M. Tsydilkovskiy, Band structure of semiconductors (Nauka, M., 1978).
[17] Zh. Pankov, Optical processes in semiconductors (Mir, M., 1973).
[18] H. L. Hartnagel, A. L. Dawar, A. K. Jain, C. Jagadish. Semiconducting Transparent Thin Films (Bristol, Institute of Physics Publishing, 1995).
[19] T. P. McLean, Prog. Semicond. 5, 53 (1960).
[20] B. F. Ormont, Introduction to physical chemistry and crystal chemistry of semiconnductors (Vysshaya shkola, M., 1973).
[21] N. Ueda, H. Hosono, R. Waseda, H. Kawazoe, Appl. Phys. Lett. 71 (4), 933 (1997).
[22] M. J. Gadre, T. L. Alford, Appl. Phys. Lett. 99, 051901 (2011).