Surface-emitting stimulated emission in high-quality ZnO thin films

Journal Article · Fri Oct 01 00:00:00 EDT 2004 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1778216· OSTI ID:20662078

Zhang, X Q; Suemune, Ikuo; Kumano, H; Wang, J; Huang, S H ^[1]

---

1. Research Institute for Electronic Science, Hokkaido University, Kita-21, Nishi-10, Sapporo 001-0021 (Japan)

High-quality ZnO thin films were grown by plasma-enhanced molecular-beam epitaxy on sapphire substrates. Three excitonic transitions associated with the valence bands A, B, and C were clearly revealed in the reflectance spectrum measured at 33 K. This result indicates that the ZnO thin films have the wurtzite crystalline structure. The emission spectra were measured with backscattering geometry at room temperature. When the excitation exceeded a certain value, linewidth narrowing, nonlinear rise of emission intensity, and the shortening of the carrier lifetime were clearly observed and these demonstrate the onset of stimulated emission. Together with the ZnO thickness dependence, we conclude that the observation of a stimulated emission in a direction perpendicular to the film surface is predominantly due to scattering of the in-plane stimulated emission by slightly remaining surface undulations in the ZnO films.

• OSTI ID: 20662078
• Journal Information: Journal of Applied Physics, Vol. 96, Issue 7; Other Information: DOI: 10.1063/1.1778216; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BACKSCATTERING
CARRIER LIFETIME
EMISSION SPECTRA
EXCITATION
EXCITONS
GEOMETRY
LINE NARROWING
MOLECULAR BEAM EPITAXY
NONLINEAR PROBLEMS
PLASMA
REFLECTIVITY
SAPPHIRE
SEMICONDUCTOR MATERIALS
STIMULATED EMISSION
SURFACES
TEMPERATURE RANGE 0273-0400 K
THICKNESS
THIN FILMS
VALENCE
ZINC OXIDES