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Defects in Irradiated ZnO Thin Films Studied by Photoluminescence and Photoconductivity

Published online by Cambridge University Press:  01 February 2011

Reinhard Schwarz ,
Rachid Ayouchi ,
Marta Brandão ,
Carlos Marques ,
Eduardo Alves ,
Melanie Pinnisch ,
Detlev Hofmann  and
Bruno Meyer
Reinhard Schwarz
Affiliation:
[email protected], Instituto Superior Tecnico, Departamento de Fisica, Lisbon, Portugal
Rachid Ayouchi
Affiliation:
[email protected], Instituto Superior Tecnico, Departamento de Fisica, Lisbon, Portugal
Marta Brandão
Affiliation:
[email protected], Instituto Superior Tecnico, Departamento de Fisica, Lisbon, Portugal
Carlos Marques
Affiliation:
[email protected], Instituto Tecnologico e Nuclear, Sacavem, Portugal
Eduardo Alves
Affiliation:
[email protected], Instituto Tecnologico e Nuclear, Sacavem, Portugal
Melanie Pinnisch
Affiliation:
[email protected], University of Giessen, Institut of Applied Physics I, Giessen, Germany
Detlev Hofmann
Affiliation:
[email protected], University of Giessen, Institut of Applied Physics I, Giessen, Germany
Bruno Meyer
Affiliation:
[email protected], University of Giessen, Institut of Applied Physics I, Giessen, Germany
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Abstract

Pulsed-laser-deposited ZnO thin films were exposed to a 1.5 MeV helium ion beam to study the changes in radiative and non-radiative recombination. We first measured photoluminescence (PL) spectra at 4.2 K excited with the 325 nm line of a HeCd laser. The as-deposited films showed a donor-bound exciton peak at 3.3567 eV attributed to Zn interstitials. After irradiation the donor-bound-exciton dominated PL spectra shifted to acceptor-bound behaviour with a signal at 3.3519 eV, tentatively attributed to Li or Na acceptors. In contrast to the approximately 30 % decrease of the PL signal near the band edge, we observed a strong concomitant enhancement of the green/orange PL band, located between 2.1 eV and 2.8 eV, by a factor of over 4. Candidates for those transitions are Li impurities and/or O vacancies. For comparison, the steady-state photocurrent decreased strongly in the irradiated region, which can also be attributed to increased non-radiative recombination through oxygen-related defects.

Keywords

defectslaser ablationoptoelectronic
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1268: Symposium EE – Defects in Inorganic Photovoltaic Materials , 2010 , 1268-EE01-05
Copyright
Copyright © Materials Research Society 2010

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References

1 Look, D.C. Claflin, B. physica status solidi (b) 241 (2004) 624.Google Scholar
2 Hofmann, D.M. Pfisterer, D. Sann, J. Meyer, B.K. Tena-Zaera, R., Munoz-Sanjose, V., Frank, T. and Pensl, G. Appl. Phys. A88 (2007) 147.Google Scholar
3 Studenikin, S.A. Golego, N. and Cocivera, M. J. Appl. Phys. 87 (2000) 2413.Google Scholar
4 Ayouchi, R. Bentes, L. Casteleiro, C. Conde, O. Marques, C.P. Alves, E. Moutinho, A.M.C. Marques, H.P. Teodoro, O. and Schwarz, R. “Photosensitivity of Nanocrystalline ZnO Films grown by PLD”, Applied Surface Science 255 (2009) 5917.Google Scholar
5 Schwarz, R. Cabeça, R., Niehus, M. Ambacher, O. Marques, C.P. Alves, E. “Stability of GaN thin films under intense MeV Helium ion irradiation”, Diamond and Related Materials 10 (2007) 1437.Google Scholar
6 Schwarz, R. Kolodzey, J. Aljishi, S. Wagner, S. Proc. of 18th IEEE Photovolt. Spec. Conf., Las Vegas, October 1985, p. 903.Google Scholar
7 Casteleiro, C. Schwarz, R. A. Maçarico, Martins, J. Vieira, M. Wuensch, F. Kunst, M. Morgado, E. Stallinga, P. Gomes, H. “Spacially-Resolved Photocapacitance Measurements to Study Defects in a-Si:H Based pin Particle Detectors”, Thin Solid Films 516 (2008) 5118.Google Scholar
8 Wysocki, J.J. IEEE Trans. on Nucl. Sci. (1963) 80.Google Scholar
9 Sellin, P. and Vaitkus, J. “New materials for radiation hard semiconductor detectors”, Nucl. Instr. and Meth. A 557 (2006) 479.Google Scholar
10 Nakamura, S. Senoh, M. Iwasa, N. and Nagahama, S. I. Appl. Phys. Lett. 67 (1995) 1868.Google Scholar
11 Ziegler, J. F. Biersack, J. P. Littmark, U. Stopping and Ranges of Ions in Solids (Pergamon, New York, 1985).Google Scholar