Substrate-Induced Solvent Intercalation for Stable Graphene Doping
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- 作者：Hyun Ho Kim ; Jae Won Yang ; Sae Byeok Jo ; Boseok Kang ; Seong Kyu Lee ; Hyojin Bong ; Geunsik Lee ; Kwang S. Kim ; Kilwon Cho
- 刊名：ACS Nano
- 出版年：2013
- 出版时间：February 26, 2013
- 年：2013
- 卷：7
- 期：2
- 页码：1155-1162
- 全文大小：628K
- 年卷期：v.7,no.2(February 26, 2013)
- ISSN：1936-086X
文摘
Here, we report a substrate-induced intercalation phenomenon of an organic solvent at the interface between monolayer graphene and a target substrate. A simple dipping of the transferred chemical vapor deposition (CVD)-grown graphene on the SiO<sub>2sub> substrate into chloroform (CHCl<sub>3sub>, CF), a common organic solvent, induces a spontaneous formation of CF clusters beneath the basal plane of the graphene as well as inside the wrinkles. The microscopic and spectroscopic observations showed the doping behavior of monolayer graphene, which indicates the adsorption of CF to monolayer graphene. Interestingly, the intercalated organic solvent showed remarkable stability for over 40 days under ambient conditions. To reveal the underlying mechanism of the stable solvent intercalation, desorption energy of CF molecules at the graphene/substrate interface was measured using Arrhenius plots of the conductance change upon time and temperature. Two stages of solvent intercalations with high desorption energies (70 and 370 meV) were observed along with the consecutive shrinkage of the solvent clusters at the basal plane and the wrinkles, respectively. Moreover, the theoretical calculation based on density functional theory (DFT) also shows the strong intercalation energy of CF between monolayer graphene and the SiO<sub>2sub> substrate, which results from the stabilization of the graphene鈥揝iO<sub>2sub> interactions. Furthermore, the thermal response of the conductance could be utilized to maintain a certain degree of p-doping of monolayer graphene, which provides the facile, sustainable, and controllable large-area doping method of graphene for future generation of printed flexible electronics.