Spallino Luisa, Vaccaro Lavinia, Sciortino Luisa, Agnello Simonpietro, Buscarino Gianpiero, Cannas Marco, Gelardi Franco Mario
Dipartimento di Fisica e Chimica, Università di Palermo, I-90123 Palermo, Italy.
Phys Chem Chem Phys. 2014 Oct 28;16(40):22028-34. doi: 10.1039/c4cp02995j.
We report the study of the visible-ultraviolet emission properties and the structural features of silica nanoparticles prepared through a laboratory sol-gel technique. Atomic force microscopy, Raman and Infrared investigations highlighted the 10 nm size, purity and porosity of the obtained nanoparticles. By using time resolved photoluminescence techniques in air and in a vacuum we were able to single out two contributions in the visible emission: the first, stable in both atmospheres, is a typical fast blue band centered around 2.8 eV; the second, only observed in a vacuum around the 3.0-3.5 eV range, is a vibrational progression with two phonon modes at 1370 cm(-1) and 360 cm(-1). By fully characterizing the spectroscopic features of this structured emission, we determine its vibronic properties and clarify the different origins with respect to the blue luminescent defect.
我们报告了通过实验室溶胶-凝胶技术制备的二氧化硅纳米颗粒的可见-紫外发射特性和结构特征的研究。原子力显微镜、拉曼光谱和红外光谱研究突出了所获得纳米颗粒的10纳米尺寸、纯度和孔隙率。通过在空气和真空中使用时间分辨光致发光技术，我们能够区分出可见发射中的两种贡献：第一种在两种气氛中都稳定，是一个典型的快速蓝带，中心约为2.8电子伏特；第二种仅在真空中约3.0-3.5电子伏特范围内观察到，是一种具有1370厘米(-1)和360厘米(-1)两种声子模式的振动进程。通过充分表征这种结构化发射的光谱特征，我们确定了其振动电子特性，并阐明了相对于蓝色发光缺陷的不同起源。
