양자소자연구실

Recently, new semiconducting 2D materials known as transition metal dichalcogenides (TMDCs) appeared, as represented by MoS2, MoSe2, WS2 and WSe2. Unlike graphene field-effect transistors (FETs) with less than ~10 of on/off ratio, the transistors made of these TMDCs can attain high current on/off ratio, which fulfills the current need for the commercial transistors, and the high mobility of TMDCs make the low power consumption of possible. In 2014, we have demonstrated the synthesis of large area MoSe2 via chemical vapor deposition on arbitrary substrates such as SiO2 and Sapphire for the first time. In addition, we have also developed a facile liquid-phase exfoliation method to improve the exfoliation efficiency for single-layer MoS2 or MoSe2 sheets. We are so confident that graphene and 2D materials will play a key role in the development of next-generation nanoscale devices or large-area displays. For the mass production of large-area graphene, CVD is the most popular method. However, handling the CVD-grown 2D materials is difficult due to their extremely thin nature when they are going through the industrial process. Another important subject of the investigation has been the interface engineering between 2D materials and other parts of devices, like the dielectrics, substrates, and channel or source/drain doping process. Integration of high-quality gate dielectrics on graphene is an important technical challenge because the quality of the interface between the dielectrics and graphene channel affects the electrical characteristics of graphene devices, such as operating voltage, scaling capability, and device reliability. To address these issues, we proposed a new approach for integration of high-k dielectrics on graphene using a functionalized graphene monolayer as