快速退火处理Au催化剂对β-Ga_2O_3纳米线阵列的影响

Influence of the Au Catalyst Rapidly Annealed at Different Temperatures on β-Ga_2O_3 Nanowire Arrays

利用化学气相沉积(CVD)法,以Au为催化剂,制备出了β-Ga_2O_3纳米线阵列。Au催化剂的密度和尺寸随快速退火处理温度的不同而改变。催化剂的形貌决定着β-Ga_2O_3纳米线阵列的形貌结构,并进一步影响其光致发光特性。X射线衍射分析显示所生长的纳米线为单斜结构的β-Ga_2O_3。扫描电子显微镜(SEM)测试表明:随着快速退火温度的升高,Au催化剂的形貌发生显著变化。在900℃下快速退火处理120 s后,生长的纳米线阵列结构致密,纳米线平均直径较小,且直径分布较为均匀。常温下以316 nm波长激发时,β-Ga_2O_3纳米线阵列光致发光谱出现紫外(393 nm)和蓝光(454 nm)发光峰。相对紫外光,蓝光的发光强度随着Au催化剂快速退火处理温度的升高而相对减弱,同时整体光致发光强度会随之增强。

The β-Ga2O3 nanowire arrays were prepared by the chemical vapor deposition （CVD） method with Au as the catalyst. The density and size of the Au catalyst were changed with the temperature of the rapid annealing treatment. The morphology and crystal structure of the β-Ga2O3 nanowire arrays were controlled by the morphology of the Au catalyst which further affected the photoluminescence properties of the nanowire arrays. The X-ray diffraction （XRD） analysis shows that the synthesized product is β-Ga2O3 of the monoclinic structure, and the scan- ning electron microscope （SEM） test results show that with the increase of the rapid annealing temperature, the morphology of the Au catalyst changes significantly. As the rapid annealing treatment carried out for 120 s at 900 ℃, the grown nanowire array is compact, the nanowire is of small average diameter and the diameter of the particles distributes uniformly. The photolumi- nescence spectrum of theβ-Ga2O3 nanowire arrays has stable ultraviolet and blue photolumines-cence peaks at 393 nm and 454 nm under the excitation of 316 nm at the room temperature, respectively. The luminescence intensity of the blue light compared to that of the ultraviolet light decreases relatively with the increase of the rapid annealing treatment temperature of the Au cata- lyst, while the overall photoluminescence intensity increases.