Pappas S D, Grammatikopoulos S, Poulopoulos P, Kapaklis V, Delimitis A, Trachylis D, Politis C
School of Engineering, Engineering Science Department, University of Patras, 26504 Patras, Greece.
J Nanosci Nanotechnol. 2011 Apr;11(4):3684-7. doi: 10.1166/jnn.2011.3814.
We present a new cost-effective method to produce substoichiometric SiO2 thin films by means of a simple sputter-coater operated at a base pressure of 1 x 10(-3) mbar. During sputtering air is introduced through a fine valve so that the sputtering gas is a mixture of air/Ar. High-resolution electron microscopy shows the formation of amorphous SiO(x) thin films for the as-deposited samples. The index x approaches 1 when the ratio of the partial pressure of air/Ar tends to 0.1. On the other hand, pure silica is formed when the ratio of the partial pressure of air/Ar approaches 0.5. The films in the as-deposited state show intense green-yellow photoluminescence. This fades away with short annealing under air at 950 degrees C. If on the other hand, prolonged annealing is performed under Argon atmosphere at 1000 degrees C, red-infrared photoluminescence is recorded due to the formation of Si nanocrystals embedded in SiO2. This simple method could be suitable for the production of thin SiO(x) films with embedded nanocrystals for optoelectronic or photovoltaic applications.
我们提出了一种新的具有成本效益的方法，通过在1×10⁻³毫巴的基础压力下运行的简单溅射镀膜机来制备亚化学计量的二氧化硅薄膜。在溅射过程中，通过一个精细阀门引入空气，使得溅射气体为空气/氩气的混合物。高分辨率电子显微镜显示，对于沉积态样品，形成了非晶态的SiOₓ薄膜。当空气/氩气的分压比趋于0.1时，指数x接近1。另一方面，当空气/氩气的分压比接近0.5时，会形成纯二氧化硅。沉积态的薄膜呈现出强烈的绿黄色光致发光。在950℃的空气中进行短时间退火后，这种光致发光会消失。另一方面，如果在1000℃的氩气气氛中进行长时间退火，由于嵌入二氧化硅中的硅纳米晶体的形成，会记录到红红外光致发光。这种简单的方法可能适用于制备用于光电子或光伏应用的嵌入纳米晶体的SiOₓ薄膜。
