摘要
A method of measuring the thermoelectric power of nano-heterostructures based on four-probe scanning tunneling microscopy is presented. The process is composed of the in-situ fabrication of a tungsten-indium tip, the precise control of the tip-sample contact and the identification of thermoelectric potential. When the temperature of the substrate is elevated, while that of the tip is kept at room temperature, a thermoelectric potential occurs and can be detected by a current voltage measurement. As an example of its application, the method is demonstrated to be effective to measure the thermoelectric power in several systems. A Seebeck coefficient of tens of IxV/K is obtained in graphene epitaxially grown on Ru （0001） substrate and the thermoelectric potential polarity of this system is found to be the reverse of that of bare Ru （0001） substrate.
A method of measuring the thermoelectric power of nano-heterostructures based on four-probe scanning tunneling microscopy is presented. The process is composed of the in-situ fabrication of a tungsten-indium tip, the precise control of the tip-sample contact and the identification of thermoelectric potential. When the temperature of the substrate is elevated, while that of the tip is kept at room temperature, a thermoelectric potential occurs and can be detected by a current voltage measurement. As an example of its application, the method is demonstrated to be effective to measure the thermoelectric power in several systems. A Seebeck coefficient of tens of IxV/K is obtained in graphene epitaxially grown on Ru （0001） substrate and the thermoelectric potential polarity of this system is found to be the reverse of that of bare Ru （0001） substrate.
基金
supported by the National Natural Science Foundation of China (Grant No. 60976089)
the National Basic Research Program of China (Grant Nos. 2007CB936802 and 2009CB929103)
