外加气流对脉冲激光烧蚀制备纳米Si晶粒尺寸分布的影响

提出一种控制脉冲激光烧蚀制备纳米Si晶粒尺寸分布的新方法。在10Pa的Ar环境中,采用脉冲激光烧蚀高阻抗单晶硅靶沉积制备了纳米Si晶薄膜。在羽辉正上方2.0cm,距靶0.3～3.0cm范围内的不同位置引入氩气流,在烧蚀点正下方2.0cm处水平放置单晶Si(111)衬底来收集制备的纳米Si晶粒。利用扫描电子显微镜观察样品表面形貌,并对衬底不同位置上纳米Si晶粒进行统计。结果表明:在不引入气流时,晶粒的尺寸随靶衬间距的增加先增大后减小,晶粒尺寸峰值出现在距靶1.7cm处;引入气流后,晶粒尺寸分布发生变化,在距靶1.7cm引入气流时晶粒尺寸峰值最大,在距靶3.0cm引入气流时晶粒尺寸峰值最小,且出现晶粒尺寸峰值的位置随着引入气流位置的增加而增大。

Influence of additional gas flow on size distribution of Si nanoparticles deposited by pulsed laser ablation

A new method for controlling the size distribution of Si nanoparticles during the process of pulsed laser ablation is proposed. The nanocrystalline silicon films were prepared by pulsed laser ablating a high resistivity single crystalline Si target in argon gas of 10 Pa. A bunch of argon gas flow was introduced at 2.0 cm above the ablation point within the axial range from 03 cm to 3.0 cm, and the as-prepared Si nanoparticles were deposited on single crystalline Si substrates located at 2.0 cm under the ablation point. Surface morphology of films was observed by scanning electron microscopy (SEM). It is found that the size of grain, without introducing gas flow, increases initially and then decreases with increasing distance between target and substrate, and the peak appears at the dista