用分子束外延设备在c面蓝宝石衬底上生长得到高质量Mg x Zn1-x O薄膜。X射线衍射显示,当Mg摩尔分数在0~32.7%范围内时,薄膜保持六方结构,(002)衍射峰半高宽为0.08°~0.12°,薄膜结晶质量与现有报道的最高水平相当。随着薄膜中M...用分子束外延设备在c面蓝宝石衬底上生长得到高质量Mg x Zn1-x O薄膜。X射线衍射显示,当Mg摩尔分数在0~32.7%范围内时,薄膜保持六方结构,(002)衍射峰半高宽为0.08°~0.12°,薄膜结晶质量与现有报道的最高水平相当。随着薄膜中Mg含量的增加,紫外发光峰由378 nm蓝移至303 nm。对Mg0.108Zn0.892O薄膜变温光致发光光谱的研究发现,束缚激子发光随温度变化存在两个不同的猝灭过程。对不同Mg含量薄膜共振拉曼光谱的研究发现,A1(LO)声子模频移与Mg含量在一定范围内呈线性关系,这为确定Mg x Zn1-x O薄膜中的Mg含量提供了一种简单高效的方法。通过拉曼光谱与X射线衍射对比研究发现,拉曼光谱在确定MgZnO材料相变时具有更高的灵敏度。最后,研究了Mg0.057Zn0.943O薄膜的变温共振拉曼光谱,对A1(LO)和A1(2LO)声子模随温度而变化的现象给出了一定的理论解释。展开更多
Mgx Zn1–x O thin films with x = 0, 0.11, 0.28, 0.44, 0.51, and 0.65 were grown by plasma-assisted molecular beam epitaxy on (0001) sapphire substrates. X-ray diffraction measurement reveals that phase separation of t...Mgx Zn1–x O thin films with x = 0, 0.11, 0.28, 0.44, 0.51, and 0.65 were grown by plasma-assisted molecular beam epitaxy on (0001) sapphire substrates. X-ray diffraction measurement reveals that phase separation of the Mgx Zn1–x O films occurred at x =0.44 and 0.51. Optical absorption spectra show that the absorption edges of the films shift to high-energy side with increasing Mg contents. In resonant Raman spectra, multiple-order Raman peaks originating from ZnO-like longitudinal optical phonons were observed. Moreover, the blue shift and the full width at half maximum of Raman scattering peaks increase continuously with x increasing from 0 to 0.28, which indicates that Zn is substituted by Mg in hexagonal lattice.展开更多
文摘用分子束外延设备在c面蓝宝石衬底上生长得到高质量Mg x Zn1-x O薄膜。X射线衍射显示,当Mg摩尔分数在0~32.7%范围内时,薄膜保持六方结构,(002)衍射峰半高宽为0.08°~0.12°,薄膜结晶质量与现有报道的最高水平相当。随着薄膜中Mg含量的增加,紫外发光峰由378 nm蓝移至303 nm。对Mg0.108Zn0.892O薄膜变温光致发光光谱的研究发现,束缚激子发光随温度变化存在两个不同的猝灭过程。对不同Mg含量薄膜共振拉曼光谱的研究发现,A1(LO)声子模频移与Mg含量在一定范围内呈线性关系,这为确定Mg x Zn1-x O薄膜中的Mg含量提供了一种简单高效的方法。通过拉曼光谱与X射线衍射对比研究发现,拉曼光谱在确定MgZnO材料相变时具有更高的灵敏度。最后,研究了Mg0.057Zn0.943O薄膜的变温共振拉曼光谱,对A1(LO)和A1(2LO)声子模随温度而变化的现象给出了一定的理论解释。
基金supported by the National Natural Science Foundation of China (Grant No 50532050)
文摘Mgx Zn1–x O thin films with x = 0, 0.11, 0.28, 0.44, 0.51, and 0.65 were grown by plasma-assisted molecular beam epitaxy on (0001) sapphire substrates. X-ray diffraction measurement reveals that phase separation of the Mgx Zn1–x O films occurred at x =0.44 and 0.51. Optical absorption spectra show that the absorption edges of the films shift to high-energy side with increasing Mg contents. In resonant Raman spectra, multiple-order Raman peaks originating from ZnO-like longitudinal optical phonons were observed. Moreover, the blue shift and the full width at half maximum of Raman scattering peaks increase continuously with x increasing from 0 to 0.28, which indicates that Zn is substituted by Mg in hexagonal lattice.
