高温退火降低碳纳米管接触电阻的实验研究

摘要

将碳纳米管有效地集成到微纳器件上实现组装是碳纳米管在众多领域得以应用的先决条件,组装后较高的接触电阻成为影响碳纳米管器件性能的重要因素,为了降低碳纳米管与电极之间的接触电阻,采用高温退火法对组装后的碳纳米管进行处理.首先,通过介电电泳法组装碳纳米管;其次,利用正交试验设计和方差分析研究高温退火过程中退火温度、保温时间和升温速率对降低碳纳米管接触电阻的影响,并获得了降低接触电阻的最优参数组合;最后,对退火前后碳纳米管的Ⅰ-Ⅴ特性进行测量、分析.结果表明:高温退火可以简单、高效地降低碳纳米管的接触电阻,退火温度是影响降阻效果的主要因素,退火处理后接触电阻的下降幅度最高可达91.59％,组装的碳纳米管退火前后的Ⅰ-Ⅴ特性曲线均呈现良好的线性.%Integrating carbon nanotubes (CNTs) into micro-and nano-devices is a critical step for applying CNTs in many fields.The high contact resistance of assembled CNTs is an important factor influencing the performance of CNT-based devices.It is possible to reduce the contact resistant of CNTs by using high temperature annealing.First,CNTs were assembled by dielectrophoresis;Second,the effects of annealing temperature,annealing time,and heating rate of reducing the contact resistance of CNTs were investigated by using orthogonal experiment design and variance analysis,and the optimal parameter combination for reducing the contact resistance was obtained;Finally,the Ⅰ-Ⅴ characteristic before and after annealing were measured respectively.Results show that the contact resistant of CNTs can be reduced efficiently by using high temperature annealing,and the annealing temperature is the leading factor causing the reduction of the resistance.After annealing,the contact resistance can be reduced at the most by 91.59％.The Ⅰ-Ⅴ curves of assembled CNTs are both linear before and after annealing.