退火温度对Au/NiO纳米颗粒复合薄膜光吸收性能的影响

Effect of Annealing Temperature on Optical Absorption Properties of Au/NiO Nano-Composite Thin Film

采用溶胶-凝胶法制备了Au/NiO纳米颗粒复合薄膜。用X射线衍射仪、原子力显微镜以及吸收光谱表征了薄膜的结构、表面形貌以及光学性能。研究结果表明:在500℃或500℃以上温度退火后,Au/NiO薄膜中存在NiO和单质Au两相,颗粒的平均大小为23～35nm。薄膜中Au颗粒基本呈球形,随着温度的升高,薄膜表面的粗糙度减小,Au颗粒长大,分布也较均匀。Au/NiO薄膜在波长550～610nm范围内具有明显的表面等离子共振吸收峰,随着退火温度的升高,吸收峰先蓝移后红移,其光吸收强度逐渐减弱。

The Au/NiO nano-composite thin films were prepared by sol-gel method. The phase structure, surface morphology and optical property of the films were characterized by X-ray diffraction, AFM and optical absorption spectra, respectively. The results show that NiO and Au phases existed in Au/NiO thin films when the annealing temperature is above 500 ℃, and the mean diameter of Au particles is about 23-35 nm. Au particles shaped in an approximate sphere. The surface roughness is reduced, the particle size of Au is increased and the distributions of Au particles became more uniform with increasing annealing temperature. The Au/NiO films had obvious surface plasmon resonance peak as the wavelength in range of 550 nm to 610 nm. The absorption peak shifts firstly to short wavelength, and then to long wavelength, and the intensity of absorption peak decreases with increasing annealing temperature.