Structural and optical properties of ZnO films grown on R–Al2O3 substrates

Abstract

Structural and optical properties of ZnO films grown on R–Al2O3 substrates by atmospheric pressure chemical-vapor deposition were investigated using x-ray diffraction and photoluminescence. The (112̄0) plane of the ZnO film tilted 0.3° with respect to the (11̄02) plane of the substrate and rotated about 7° around the normal of the sample surface. Symmetric (112̄0) and asymmetric (202̄2) x-ray reflection on ZnO films with different thicknesses were carried out. Comparison with photoluminescence measurements allowed us to conclude that the optical properties of the ZnO films are predominately determined by the in-plane, rather than out-of-plane, structural features.

Metalorganic chemical vapor deposition and characterizations of epitaxial MgxZn1−xO (0⩽x⩽0.33) films on r-sapphire substrates

“…The in-plane crystalline orientation was analyzed using j-scans as shown in Fig. 5 [12,14]. These results show that the crystalline structure of the Mg x Zn 1Àx O films grown on r-sapphire substrates using a buffer layer is hexagonal (wurtzite), similar to the ZnO films grown r-sapphire substrates.…”

“…The ZnO/(0 1 % 1 2) r-sapphire system possesses anisotropic properties which are useful for various important applications such as acousto-optic, and surface acoustic wave (SAW) devices [12,13]. The epitaxial relationships between ZnO and r-sapphire is known to be [12,14]: (1 1 % 2 0) ZnOJ(0 1 % 1 2) Al 2 O 3 and [0 0 0 1] ZnOJ[0 % 1 1 1] Al 2 O 3 . In this orientation, the c-axis of ZnO lies in the plane of the film.…”

High-quality ZnO films grown by atmospheric pressure metal– organic chemical vapor deposition

“…So, AP-MOCVD is a promising way to grow high-quality ZnO films. However, there have been only a few investigations of AP-MOCVD growth of ZnO films reported in the literature [12][13][14][15]. The problem for MOCVD growth of ZnO is that Zn precursors are highly reactive with O precursors (usually oxygen or water), so that pre-reaction in the gas phase occurs easily and usually produces white powder on the substrate.…”

MOCVD growth and properties of ZnO thin films on LiNbO3 substrates

“…It is also well known as an outstanding piezoelectric material for surface acoustic wave (SAW) opto-electronic devices used in delay lines, filters and resonators in wireless communication and signal processing. Many different deposition methods, such as metal organic chemical vapor deposition (MOCVD) [1], molecular beam epitaxy (MBE) [2], sputtering [3], chemical vapor deposition (CVD) [4,5] laser deposition (PLD) [6,7], spray pyrolysis [8] and also the sol-gel technique [9], have been used for the growth of ZnO films on various substrates. Among these methods, the MOCVD technology is particularly interesting-not only because it leads to high-quality films, but also because it is applicable to industrial mass-production.…”