反应条件对硅烷均相热解产物形态和组成的影响

Effects of Operating Conditions on Morphology and Components of Products in Silane Homogeneous Pyrolysis

摘要:

本文在垂直的空管反应器内，采用硅烷热解法得到不同反应条件下的均相热解非晶硅粉末产物，利用红外漫反射池和扫描电子显微镜等表征方法对所得产物进行了分析，研究论述了反应温度、操作气速和硅烷浓度对非晶硅产物微观形态、粒度分布和Si-H结构组成等性质的影响；采用红外漫反射方法分析Si-H结构，将SiH2和SiH结构的吸收峰量化，能够有效地由非晶硅的结构角度帮助理解硅烷均相热解过程的机理。结果表明，反应温度越高（550℃）、操作气量越低（600mL/min）、硅烷浓度含量越高(5%)时，产物的粒度越大，但其粒度分布范围仅受反应温度影响；对于产物的Si-H结构，反应温度影响最强，硅烷浓度影响很小。

Abstract:

In this paper, the homogeneous products by silane pyrolysis in a vertical tube reactor were obtained under different operating conditions. The characterization techniques of FT-IR and SEM were applied to investigate the morphology, particle size distribution and components of the products. The effects of the operating conditions including the operating temperature, total gas flux and inlet silane concentration on the properties of the amorphous silicon products were studied. The content of hydrogen was especially analyzed by infrared diffuse reflection, which allows quantization of the special absorption peaks in SiH2 and SiH structures and helps with a further understanding on the mechanism of silane homogeneous pyrolysis by the structure form of the amorphous silicon. The results reveals that the product shows larger particle size under higher operating temperature(550℃), lower gas velocity(600mL/min) and higher silane concentration(5%). And higher operating temperature also results in wider range of particle size distribution. Besides, the Si-H structure is mostly affected by temperature and least by silane concentration.