SiC低维纳米材料压阻特性研究

发布时间：2018-04-12 10:21

  本文选题：有机前驱体 + 热解　； 参考：《中国矿业大学》2017年硕士论文

【摘要】：传感器技术是人类认识和改造世界的“五官”,是衡量现代化进程的关键技术之一。压阻式压力传感器因其灵敏度高、稳定性好、能耗低、易于集成等优点,在航天航空、石油化工、医疗、汽车等领域应用广泛。在众多传感器中,半导体压力传感器因其性能优异而备受关注。碳化硅(SiC)是第三代半导体,具有宽带隙、高热导率、高电子迁移率、较高击穿电压以及优异的力学性能,在高温、高频和高辐射等苛刻环境下的器件应用上具有显著优势。围绕SiC压力传感器研发,已有的研究工作主要集中在薄膜、多晶和单晶块体材料。低维纳米材料因其特有的纳米效应和独特的晶体结构,展现出了传统体材料无法比拟的高灵敏的压阻特性,为新型高效压力传感器的研发提供了契机。本论文以高灵敏SiC压力传感器研发为导向,首先采用有机前驱体热解工艺,制备出具有不同掺杂元素和形貌的SiC一维纳米材料,然后利用原子力显微镜的导电模式,对其压阻特性进行系统检测和分析。综合本论文工作,主要结论如下:(1)以有机前驱体(聚硅氮烷)热解工艺,B_2O_3为掺杂剂,Co(NO_3)_2为催化剂,在纯Ar气氛中,制备出了单晶B掺杂3C-SiC纳米线。压阻特性检测分析表明:所制备的纳米线在(?)晶向表现为负压阻,在51.7~181.0 nN的压力下,其压阻系数(?)为-8.83~-103.42×10-11 Pa-1,应变系数高达-620.5,相比较已有报道的最高值,提高了近8倍。(2)以有机前驱体(聚硅氮烷)热解工艺,B_2O_3为掺杂剂,未引入催化剂,在纯Ar气氛中,制备出了单晶B掺杂SiC纳米带。压阻特性检测分析表明:所制备的纳米带在晶向表现为负压阻。在104.3~223.6 nN的压力下,压阻系数(?)为-29.96~-303.90×10-11 Pa-1,计算获得的应变系数高达-1823.4,比B掺杂SiC纳米线的应变系数提高3倍左右。(3)以有机前驱体(聚硅氮烷)热解工艺,Co(NO_3)_2为催化剂,在N_2/Ar混合(其中N2作为掺杂剂)气氛中,制备出了单晶N掺杂SiC纳米线。在28.2nN的压力下,测得压阻系数(?)为~4.31×10-11 Pa-1,应变系数为25.9。优化选择波长为405 nm、光功率为62.4 mW的紫外光进行激发时,纳米线压阻系数为~11.77×10-11 Pa-1,相应的应变系数达到70.6,比暗态下提高了近3倍。
[Abstract]:The sensor technology is the human understanding and transforming the world "features", is one of the key technologies to measure modernization. Piezoresistive pressure sensor because of its high sensitivity, good stability, low energy consumption, easy integration, etc., in aerospace, petrochemical, medical, automotive and other fields are widely applied. In many sensors, semiconductor the pressure sensor because of its excellent properties have attracted much attention. Silicon carbide (SiC) is the third generation of semiconductor with wide band gap, high thermal conductivity, high electron mobility, high breakdown voltage and excellent mechanical properties at high temperature, and has the advantages of application of high frequency and high radiation and other harsh environments around the SiC pressure device. The sensor research and development, the research has focused on thin film, polycrystalline and single crystal bulk materials. Low dimensional nano materials because of its unique nano effect and unique crystal structure, showing the traditional bulk materials The piezoresistive properties of high sensitive material can not be compared, provides an opportunity for the development of new type high pressure sensor. This paper takes the high sensitive SiC pressure sensor research and development oriented, first by the organic precursor pyrolysis process, the preparation of SiC one-dimensional nano material with different doping elements and morphology, and then conducting mode by atomic force microscopy the system for detection and analysis of the piezoresistive properties. In this paper, the main conclusions are as follows: (1) the organic precursor (polysilazane) pyrolysis process B_2O_3 as doping agent, Co (NO_3) _2 as catalyst, in pure Ar atmosphere, prepared single crystal B doped 3C-SiC nanowires. The piezoresistive properties analysis showed that the prepared nanowires in the (?) crystal to show negative resistance in 51.7~181.0 nN under the pressure of the piezoresistive coefficient (?) -8.83~-103.42 * 10-11 Pa-1, the strain coefficient of up to -620.5, compared to the existing reports 鐨勬渶楂樺，

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