Resonant Raman scattering study of BexZn1−xO thin films grown on sapphire by molecular beam epitaxy

Abstract

Resonance Raman spectra of Be[Formula: see text]Zn[Formula: see text]O alloy materials were studied using 325 nm Laser. The research showed that the Raman spectra of Be[Formula: see text]Zn[Formula: see text]O alloys presents a dual-mode vibration. Compare Be[Formula: see text]Zn[Formula: see text]O alloy with ZnO single crystal, the A1 (LO) phonon vibration mode of Be[Formula: see text]Zn[Formula: see text]O alloy moved to the larger wave number direction. The position of A1 (LO) phonon vibration modes of Be[Formula: see text]Zn[Formula: see text]O and Be[Formula: see text]Zn[Formula: see text]O was 580 cm[Formula: see text] and 582 cm[Formula: see text], respectively. In addition, the temperature-dependent Raman spectroscopy was employed for Be[Formula: see text]Zn[Formula: see text]O, and the phonon mode frequency shift with temperature was studied in detail. Finally, the stability of the polar and nonpolar Be[Formula: see text]Zn[Formula: see text]O alloy materials was studied using resonance Raman spectroscopy. The results showed that the A1 (LO) phonon mode frequency of polar Be[Formula: see text]Zn[Formula: see text]O alloy remained in the same position, while the nonpolar Be[Formula: see text]Zn[Formula: see text]O alloys moved nearly 3.5 cm[Formula: see text] to larger direction after being placed in the air for two years. The reason may be that the stability of the nonpolar Be[Formula: see text]Zn[Formula: see text]O alloy is relatively poor upon interaction with molecule such as H2O, O2 in the air.