前驱体热解法制备硅基化合物纳米材料的形貌调控研究
发布时间：2018-07-31 09:32
【摘要】： 硅基化合物纳米材料是重要的半导体材料,因其独特的物理化学性能在纳米电子器件和光电子器件中有着广泛的潜在应用前景,其制备和应用研究一直受到国内外的普遍关注。 本论文采用催化剂辅助热解有机前驱体聚硅氮烷在优化的条件下合成了多种硅基化合物纳米材料。这种方法简单,仅包括三个步骤:有机前驱体低温交联固化、球磨粉碎和高温热解。理论上,通过调节工艺参数如前驱体的组分、气氛、催化剂、热解温度等,可以得到不同形貌的纳米材料。当使用Fe粉和FeCl2粉作为催化剂时,在高纯氮气保护下,以10℃/min升温至1250℃热解2 h,分别合成了束状Si_3N_4纳米线和Y型枝状Si_3N_4纳米线;在同样条件下,当使用氧化铝基片上的FeCl2膜作为催化剂时,合成了团簇状SiO_2非晶纳米线。当使用硅片上镀有的5 nm厚Fe膜作催化剂,前驱体的量为0.8 g,在高纯氮气保护下,以10℃/min升温至1250℃热解2 h,合成了网络枝状Si_3N_4纳米线,而且前驱体的量越充足,升温速率越快,Fe膜越厚有利于网络枝状Si_3N_4纳米线的形成。当以硅片上5 nm厚Fe膜作催化剂,前驱体的量为0.5 g,在高纯氮气保护下,以5℃/min升温至1250℃热解2 h,合成了Si_3N_4纳米线阵列,而且前驱体的量相对较少,保温时间较短时,有利于阵列的形成;在其他的条件都相同时,当氧分压较高时,合成了Si_3N_4/SiO_2同轴纳米电缆阵列。 用热解法制备Si_3N_4纳米材料的化学反应历程,可能是前驱体交联固化后得到的SiCN化合物与氧气反应生成SiO_2,SiO_2和前驱体热解产生的Si或C反应生成亚稳态的SiO,SiO与CO及含氮气相反应生成Si_3N_4。用热解法制备的硅基化合物纳米材料的生长机制,是气-液-固(VLS)机制,论文还给出了相应的生长模型。论文测试了部分合成的氮化硅纳米材料的光致发光性能,并探讨了其发光机理,发光峰的中心位置在1.9+0.2 eV和3.43+0.3 eV。
[Abstract]:Silicon based compound nanomaterials are important semiconductor materials. Because of their unique physical and chemical properties, they have wide potential applications in nano-electronic devices and optoelectronic devices. In this paper, a variety of silicon-based nanomaterials were synthesized by using catalyst assisted pyrolysis organic precursor polysiloxane under optimized conditions. This method is simple and consists of only three steps: low temperature crosslinking and curing of organic precursor, milling and high temperature pyrolysis. In theory, different morphologies of nanomaterials can be obtained by adjusting process parameters such as composition of precursor, atmosphere, catalyst, pyrolysis temperature and so on. When Fe powder and FeCl2 powder were used as catalysts, the bunchy Si_3N_4 nanowires and Y-type dendritic Si_3N_4 nanowires were synthesized by pyrolysis at 10 鈩，
本文编号：2155167
[Abstract]:Silicon based compound nanomaterials are important semiconductor materials. Because of their unique physical and chemical properties, they have wide potential applications in nano-electronic devices and optoelectronic devices. In this paper, a variety of silicon-based nanomaterials were synthesized by using catalyst assisted pyrolysis organic precursor polysiloxane under optimized conditions. This method is simple and consists of only three steps: low temperature crosslinking and curing of organic precursor, milling and high temperature pyrolysis. In theory, different morphologies of nanomaterials can be obtained by adjusting process parameters such as composition of precursor, atmosphere, catalyst, pyrolysis temperature and so on. When Fe powder and FeCl2 powder were used as catalysts, the bunchy Si_3N_4 nanowires and Y-type dendritic Si_3N_4 nanowires were synthesized by pyrolysis at 10 鈩，
本文编号：2155167
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