Research Overview
Electrical transport measurement under various conditions is the main tool of my research. Simple experimental method where current (voltage) is applied through the sample and voltage (current) is measured is conducted to get the information of resistance based on Ohm’s law. Even though the basic concept and method are very simple, transport measurement is very powerful tool to explore the properties of materials from metal to insulator with optimized electrode configuration and under various experimental environments. For example, we can distinguish metal and semiconductor by resistance behavior depending on temperature, we can modulate the conductance of semiconductors by applying gate voltage with three-electrode transistor configuration, we can construct Fermi surface of metal by magnetoresistance oscillations depending on magnetic field and so on.
Recently, I am interested in the two dimensional materials like graphene and transition metal dichalcogenides from their basic properties to device applications. Different from previous research, the functional oxides with unique properties such as high-k or ferroelectrics are used as substrates to control the physical properties and to improve the device performance. The features of functional oxide thin films can be well characterized by quantum conductance of graphene, which is utilized to design high performance devices. Moreover, the heterostructures with two-dimensional materials and oxide thin film have been expected to show interesting phenomena due to interface effects.
Recently, I am interested in the two dimensional materials like graphene and transition metal dichalcogenides from their basic properties to device applications. Different from previous research, the functional oxides with unique properties such as high-k or ferroelectrics are used as substrates to control the physical properties and to improve the device performance. The features of functional oxide thin films can be well characterized by quantum conductance of graphene, which is utilized to design high performance devices. Moreover, the heterostructures with two-dimensional materials and oxide thin film have been expected to show interesting phenomena due to interface effects.