Defects in Irradiated ZnO Thin Films Studied by Photoluminescence and Photoconductivity

被引：0

作者：

Schwarz, Reinhard ^{[1
,2
]}

Ayouchi, Rachid ^{[1
,2
]}

Brandao, Marta ^{[1
,2
]}

Marques, Carlos ^{[3
]}

Alves, Eduardo ^{[3
]}

Pinnisch, Melanie ^{[4
]}

Hofmann, Detlef ^{[4
]}

Meyer, Bruno ^{[4
]}

机构：

[1] Inst Super Tecn, Dept Phys, Lisbon, Portugal

[2] Inst Super Tecn, ICEMS, Lisbon, Portugal

[3] ITN, Lisbon, Portugal

[4] Univ Giessen, Phys Dept 1, Giessen, Germany

来源：

DEFECTS IN INORGANIC PHOTOVOLTAIC MATERIALS | 2010年 / 1268卷

关键词：

D O I：

10.1557/PROC-1268-EE01-05

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

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.

引用

页码：111 / 116

页数：6

共 11 条

[1] Photosensitivity of nanocrystalline ZnO films grown by PLD
Ayouchi, R.
Bentes, L.
Casteleiro, C.
Conde, O.
Marques, C. P.
Alves, E.
Moutinho, A. M. C.
Marques, H. P.
Teodoro, O.
Schwarz, R.
[J]. APPLIED SURFACE SCIENCE, 2009, 255 (11) : 5917 - 5921
[2] Spatially-resolved photocapacitance measurements to study defects in a-Si:H based p-i-n particle detectors
Casteleiro, C.
Schwarz, R.
Mardolcar, U.
Macarico, A.
Martins, J.
Vieira, M.
Wuensch, F.
Kunst, M.
Morgado, E.
Stallinga, P.
Gomes, H. L.
[J]. THIN SOLID FILMS, 2008, 516 (15) : 5118 - 5121
[3] Hofmann DM, 2007, APPL PHYS A-MATER, V88, P147, DOI [10.1007/s00339-007-3956-2, 10.1007/S00339-007-3956-2]
[4] P-type doping and devices based on ZnO
Look, DC
Claftin, B
[J]. PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, 2004, 241 (03): : 624 - 630
[5] HIGH-POWER INGAN SINGLE-QUANTUM-WELL-STRUCTURE BLUE AND VIOLET LIGHT-EMITTING-DIODES
NAKAMURA, S
SENOH, M
IWASA, N
NAGAHAMA, S
[J]. APPLIED PHYSICS LETTERS, 1995, 67 (13) : 1868 - 1870
[6] Stability of GaN films under intense MeV He ion irradiation
Schwarz, R.
Cabeca, R.
Morgado, E.
Niehus, M.
Ambacher, O.
Marques, C. P.
Alves, E.
[J]. DIAMOND AND RELATED MATERIALS, 2007, 16 (4-7) : 1437 - 1440
[7] Schwarz R., 1985, P 18 IEEE PHOT SPEC, P903
[8] New materials for radiation hard semiconductor dectectors
Sellin, PJ
Vaitkus, J
[J]. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 2006, 557 (02) : 479 - 489
[9] Carrier mobility and density contributions to photoconductivity transients in polycrystalline ZnO films
Studenikin, SA
Golego, N
Cocivera, M
[J]. JOURNAL OF APPLIED PHYSICS, 2000, 87 (05) : 2413 - 2421
[10] Wysocki J.J., 1963, IEEE T NUCL SCI, P80

← 1 2 →