Nano Electronics Laboratory, Samsung Advanced Institute of Technology , Suwon, Gyeonggi-do 443-803, South Korea.
ACS Nano. 2015 Jan 27;9(1):602-11. doi: 10.1021/nn505925u. Epub 2015 Jan 9.
We investigated systematic modulation of the Dirac point voltage of graphene transistors by changing the type of ionic liquid used as a main gate dielectric component. Ion gels were formed from ionic liquids and a non-triblock-copolymer-based binder involving UV irradiation. With a fixed cation (anion), the Dirac point voltage shifted to a higher voltage as the size of anion (cation) increased. Mechanisms for modulation of the Dirac point voltage of graphene transistors by designing ionic liquids were fully understood using molecular dynamics simulations, which excellently matched our experimental results. It was found that the ion sizes and molecular structures play an essential role in the modulation of the Dirac point voltage of the graphene. Through control of the position of their Dirac point voltages on the basis of our findings, complementary metal-oxide-semiconductor (CMOS)-like graphene-based inverters using two different ionic liquids worked perfectly even at a very low source voltage (V(DD) = 1 mV), which was not possible for previous works. These results can be broadly applied in the development of low-power-consumption, flexible/stretchable, CMOS-like graphene-based electronic devices in the future.
我们通过改变用作主栅介电组件的离子液体的类型来研究石墨烯晶体管中狄拉克点电压的系统调制。离子凝胶由离子液体和基于非三嵌段共聚物的粘合剂形成，涉及紫外线照射。对于固定的阳离子（阴离子），随着阴离子（阳离子）尺寸的增加，狄拉克点电压向更高的电压移动。使用分子动力学模拟充分理解了通过设计离子液体来调制石墨烯晶体管的狄拉克点电压的机制，这些模拟与我们的实验结果非常吻合。结果发现，离子大小和分子结构在调制石墨烯的狄拉克点电压方面起着重要作用。根据我们的发现，通过控制它们的狄拉克点电压的位置，即使在非常低的源电压（V（DD）= 1 mV）下，使用两种不同离子液体的互补金属氧化物半导体（CMOS）类似石墨烯的基于逆变器也能完美工作，这在以前的工作中是不可能的。这些结果可以广泛应用于未来低功耗、灵活/可拉伸、类似 CMOS 的基于石墨烯的电子设备的开发。
