二氧化钛阵列的制备及其光学性能

Synthesis and Optical Properties of TiO2 Array

以水热法制备了由纳米棒组成的二氧化钛阵列。通过控制反应时间,对组成阵列的二氧化钛纳米棒的尺寸进行调节。利用扫描电镜和X射线衍射光谱分析了样品的形貌和晶体结构,发现将反应时间由4h延长至8h,二氧化钛纳米棒的直径由100nm增大到200nm。利用紫外-可见吸收光谱测量了样品的光吸收特性,发现了尺寸效应引起的吸收边和带隙变化,反应时间由4h延长至8h,样品带隙由3.09eV变化至2.97eV。利用荧光光谱研究样品的光致发光性能,发现了样品的近带边发光(382nm左右)、自陷激子发光(420nm左右)、束缚激子发光(456nm左右)和缺陷能级发光(492nm左右)。

TiO2 array was synthesized by hydrothermal method. The scanning electron microscopy(SEM) and X-ray diffraction(XRD) are used to detect their morphology and structure. The average diameter of TiO2 nanorods was increased from 100 nm to 200 nm,when the hydrothermal reaction time changed from 4 h to 8 h. UV-vis spectra were used to detect their absorption properties. The TiO2 array with shorter diameter shows blue shift of absorption edge and broadened band gap. The band gap of TiO2 nanorod was decreased from 3.09 eV to 2.97 eV,when the hydrothermal reaction time changed from 4 h to 8 h. Photoluminescence spectra were used to detect their optical properties. Near absorption edgee mission(about 382 nm),self-trapped exciton emission(about 420 nm),bound exciton emission(about 456 nm),and defect site emission(about 492 nm) are obtained under the examination by PL spectra.