Visible luminescence from silicon surfaces fabricated by femtosecond laser pulses
-
摘要: 采用钛宝石飞秒脉冲激光对单晶硅在空气中进行辐照,研究了硅表面在不同扫描速度和能量密度下的光致荧光特性。光致荧光谱(PL)测量表明,在样品没有退火处理的情况下,激光扫描区域观察到橙色荧光峰(603 nm)和红色荧光带(680 nm附近)。扫描电子显微镜(SEM)测量显示,在飞秒脉冲激光辐照硅样品的过程中硅表面沉积了大量的纳米颗粒。利用傅里叶变换红外光谱仪(FT-IR)检测到了低值氧化物SiOx(x<2)的存在,并且结合能谱仪(EDS)检测结果发现氧元素在光致发光中起着重要作用。研究表明:603 nm处橙色荧光峰来自微构造硅表面低值氧化物SiOx,680 nm附近红色荧光带来自量子限制效应。同时样品表面硅纳米颗粒的尺寸和氧元素的浓度分别决定了红色荧光带和橙色荧光的强度,通过调节飞秒激光脉冲的扫描速度和能量密度,可以有效地控制样品的荧光强度。Abstract: The photoluminescence (PL) from microstructured silicon fabricated by femtosecond laser pulses in air was studied. In photoluminescence spectra measurements, the orange PL peak (603 nm) and the red PL band (near 680 nm) were observed even without annealing. The scanning electron microscope images (SEM) revealed that lots of nanoclusters and nanoparticles were deposited on the silicon surface. Fourier transform infrared spectroscopy (FT-IR) and energy dispersive spectroscopy (EDS) indicated that the oxygen element played an important role in the photoluminescence. The results confirmed that the red PL band and the orange PL peaks derived from the recombination of the quantum confinement effect and the suboxides (SiOx), respectively. Meanwhile, The oxygen content determined the orange PL intensity, and the size of nanoparticles decided the quantum confinement effect.
点击查看大图
计量
- 文章访问数: 1304
- HTML全文浏览量: 170
- PDF下载量: 410
- 被引次数: 0