Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Nano Lett. 2012 Jan 11;12(1):182-7. doi: 10.1021/nl2032734. Epub 2011 Dec 19.
We report a route to noncovalently latch dipolar molecules on graphene to create stable chromophore/graphene hybrids where molecular transformation can be used as an additional handle to reversibly modulate doping while retaining high mobilities. A light switchable azobenzene chromophore was tethered to the surface of graphene via π-π interactions, leading to p-doping of graphene with an hole concentration of ~5 × 10(12) cm(-2). As the molecules switch reversibly from trans to cis form the dipole moment changes, and hence the extent of doping, resulting in the modulation of hole concentration up to ~18% by alternative illumination of UV and white light. Light-driven conductance modulation and control experiments under vacuum clearly attribute the doping modulation to molecular transformations in the organic molecules. With improved sensitivities these "light-gated" transistors open up new ways to enable optical interconnects.
我们报告了一种非共价键固定偶极分子在石墨烯上的方法，以创建稳定的生色团/石墨烯杂化物，其中分子转变可作为附加手段来可逆地调节掺杂，同时保持高迁移率。通过 π-π 相互作用将光致变色的偶氮苯生色团键合到石墨烯表面，导致石墨烯 p 掺杂，空穴浓度约为 5×10(12)cm(-2)。当分子可逆地从反式到顺式转变时，偶极矩发生变化，因此掺杂程度发生变化，通过交替照射紫外光和白光，空穴浓度可调制高达约 18%。在真空中进行的光驱动电导调制和控制实验清楚地表明，掺杂调制归因于有机分子中的分子转变。随着灵敏度的提高，这些“光控”晶体管为实现光学互连开辟了新途径。
