| AVS 54th International Symposium | |
| Electronic Materials and Processing | Thursday Sessions |
| Session EM-ThM |
| Session: | Zinc Oxide |
| Presenter: | Y.J. Li, Pacific Northwest National Laboratory |
| Authors: | Y.J. Li, Pacific Northwest National Laboratory T.C. Kaspar, Pacific Northwest National Laboratory T.C. Droubay, Pacific Northwest National Laboratory S. Shutthanandan, Pacific Northwest National Laboratory S. Thevuthasan, Pacific Northwest National Laboratory P. Nachimuthu, Pacific Northwest National Laboratory S.A. Chambers, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
As a wide bandgap semiconductor with good light emission properties, ZnO has attracted much interest because of its potential as a multifunctional material. Recent developments in bulk crystal and epitaxial film growth, along with advances in characterization methods, have expanded our understanding of this material, and created possibilities for ZnO-based optoelectronic, spin electronic, and transparent electronic applications. However, progress has been impeded by a lack of understanding and control of dopants, impurities and defects in ZnO. Difficulties in p-type doping of ZnO result from high background donor compensation of acceptors. One of the suspected background shallow donors in ZnO is H, which has been suggested to be readily incorporated during growth.1-2 Theoretical calculations have predicted that H can exhibit a substitutional (on the O site) multi-center bonding configuration (HO).3 However, there is thus far no experimental evidence for HO in ZnO. The focus of this study is to use nuclear reaction analysis to determine the local structural environment of H in ZnO. ZnO films are being grown in ultra-high purity H2 at 500°C by pulsed laser deposition. The H(15N,αγ)12C and H(19F,αγ)16O nuclear reactions are being used in channeling and random directions to determine the position of H in the lattice. Initial results indicate that growth of ZnO in 10 mTorr H2 at 500°C results in a total H concentration of ~1 x 1020 cm-3. High-resolution x-ray diffraction is being used to characterize out-of-plane and in-plane lattice parameters of the doped phase. The effects of growth conditions on crystallinity as well as H concentration and position in the lattice are being investigated, and will be described in this talk.
1 C.G. Van de Walle, Phys. Rev. Lett. 85, 1012-1015 (2000).
2 D.M. Hofmann, A. Hofstaetter, F. Leiter, H. Zhou, F. Henecker, B.K. Meyer, S.B. Orlinskii, J. Schmidt, and P.G. Baranov, Phy. Rev. Lett. 88, 5504 (2002).
3 A.Janotti and C.G. Van der Walle, Nature Materials 6, 44 (2007).