Cation–π interactions between molecules and graphene are known to have a profound effect on the properties of the molecule/graphene nanohybrids and motivate this study to quantify the attachment of the rhodamine 6G (R6G) dye molecules on graphene and the photocarrier transfer channel formed across the R6G/graphene interface. By increasing the R6G areal density of the R6G on graphene field‐effect transistor (GFET) from 0 up to ≈3.6 × 10¹³ cm⁻², a linear shift of the Dirac point of the graphene from originally 1.2 V (p‐doped) to −1 V (n‐doped) is revealed with increasing number of R6G molecules. This indicates that the attachment of the R6G molecules on graphene is determined by the cation–π interaction between the NH+ in R6G and π electrons in graphene. Furthermore, a linear dependence of the photoresponse on the R6G molecule concentration to 550 nm illumination is observed on the R6G/graphene nanohybrid, suggesting that the cation–π interaction controls the R6G attachment configuration to graphene to allow formation of identical photocarrier transfer channels. On R6G/graphene nanohybrid with 7.2 × 10⁷ R6G molecules, high responsivity up to 5.15 × 10² A W⁻¹ is obtained, suggesting molecule/graphene nanohybrids are promising for high‐performance optoelectronics.

中文翻译：

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罗丹明/石墨烯异质结构中阳离子-π相互作用辅助分子的附着和光子转移

已知分子与石墨烯之间的阳离子-π相互作用对分子/石墨烯纳米杂化物的性质具有深远的影响，并激发了这项研究以量化若丹明6G（R6G）染料分子在石墨烯上的附着以及形成的光载流子转移通道R6G /石墨烯接口。通过将石墨烯场效应晶体管（GFET）上的R6G的R6G面密度从0增加到≈3.6×10 ¹³ cm ^-2随着R6G分子数量的增加，石墨烯的狄拉克点从最初的1.2 V（p掺杂）到-1 V（n掺杂）线性变化。这表明R6G分子在石墨烯上的附着取决于R6G中NH +和石墨烯中π电子之间的阳离子-π相互作用。此外，在R6G /石墨烯纳米杂化物上观察到光响应对R6G分子浓度至550 nm照射的线性依赖性，这表明阳离子-π相互作用控制了R6G与石墨烯的附着构型，从而允许形成相同的光载流子传输通道。在具有7.2×10 ⁷ R6G分子的R6G /石墨烯纳米杂化物上，高响应度可达5.15×10 ² AW ^-1 获得的分子结构表明分子/石墨烯纳米杂化材料有望用于高性能光电子学。