Nano Res.[碳]│国防科技大学秦石乔教授团队、东南大学赵蓓教授团队：异质结超洁净界面突破

背景介绍

二维范德华异质结为调控低维材料电荷输运、能带排列与多体相互作用提供了关键平台，在新型电子、光电子器件中应用前景广阔。其中，石墨烯基异质结对界面状态高度敏感，界面电荷转移、静电屏蔽与层间耦合仅发生在原子尺度区域。然而，传统多层转移工艺依赖聚合物辅助，难以完全消除残留聚合物与吸附物，这些杂质会引入界面陷阱态与电荷散射中心，严重降低载流子迁移率、亚阈值摆幅与开关比。对于双层石墨烯而言，其静电调制与带隙调控高度依赖洁净界面，界面污染已成为制约器件电调制效率的核心瓶颈，实现原子级洁净界面成为领域研究重点与难点。

成果简介

近日，国防科技大学秦石乔教授团队、东南大学赵蓓教授团队联合设计聚乙烯醇缩丁醛（PVB）辅助一步转移技术，成功构筑超洁净氯氧化铬/双层石墨烯/氮化硼（CrOCl/双层石墨烯/BN）异质结，实现石墨烯输运性能的极大提升。在无需退火处理条件下，器件开关比突破10⁸，双栅调控能力、低漏电流与稳定性优异，为高性能二维电子器件提供全新方案。

图文导读

该研究创新采用一步转移策略：仅用PVB薄膜一次性完成CrOCl、石墨电极、石墨烯与BN衬底的精准堆叠，最大限度减少聚合物接触，从根源上抑制界面残留与裂纹产生。原子级表征显示，一步转移制备的异质结界面粗糙度仅0.778 nm，一步转移异质结中CrOCl与双层石墨烯之间的表面电位差为145 mV，高于多步转移异质结中观测到的表面电位差（40 mV），表明一步转移异质结中的CrOCl/石墨烯界面表现出更强的电子耦合，可能使CrOCl能够通过电场更有效地调节石墨烯的载流子浓度和能带结构。扫描透射电子显微镜证实PVB辅助一步转移技术制备的异质结中CrOCl与双层石墨烯之间的原子级界面，远优于传统工艺，实现无杂质、无缝隙的完美范德华键合。对比不同工艺制备的BN/BLG/CrOCl异质结器件的电学性能，发现一步转移技术制备的器件的开媲美MoS₂等典型二维半导体，为双层石墨烯的带隙调控与高效开关应用提供全新路径。

Figure 1 PVB-assisted one-step transfer technology for constructing CrOCl/graphene/BN heterojunctions. (a) Detailed process of the transfer technique. (b) Schematic diagram of typical CrOCl crystal structure. (c) Optical image of the CrOCl/graphene/BN heterojunction. (d) Raman characterization of the CrOCl/graphene/BN heterojunction.

Figure 2 Microscopic morphological characterization of the interface quality of heterojunctions fabricated by different transfer techniques. (a) AFM image of the heterojunction prepared by the one-step transfer technology. (b) Surface potential distribution of the heterojunction prepared by the one-step transfer technology. (c) AFM image of the heterojunction prepared by the multi-step transfer technology. (d) Surface potential distribution of the heterojunction prepared by the multi-step transfer technology. (e-h) Atomic-level interface characterization of the heterojunction prepared by the one-step transfer technology: (e) STEM image; (f) EDS spectrum of Cr; (g) EDS spectrum of Cl; (h) EDS spectrum of C. (i-l) Atomic-level interface characterization of the heterojunction prepared by the multi-step transfer technology: (i) STEM image; (j) EDS spectrum of Cr; (k) EDS spectrum of Cl; (l) EDS spectrum of C.

Figure 3 Electrical characterization of BN/graphene/CrOCl heterojunction. (a) Schematic diagram of the device structure. (b) Transfer characteristic curve of the device fabricated by the multi-step transfer technology, with an optical image inset. (c) V_bg-dependent top-gate transfer characteristic curves of the device fabricated by the multi-step transfer technology: V_bg = -40 V, -20 V, 0 V, 20 V, 40 V. (d) Transfer characteristics curve of the device fabricated by the one-step transfer technology. (e) V_bg-dependent top-gate transfer characteristics curve of the device fabricated by the one-step transfer technology: V_bg = -40 V, -20 V, 0 V, 20 V, 40 V. (f) On/off ratio variation with V_bg for different devices fabricated by the two techniques at different V_bg values.

Figure 4 Electrical characterizations of BN/graphene/CrOCl heterostructure by one-step transfer technology. (a) Optical and device schematic image of heterostructure. (b) The drain source current-drain source voltage (I_ds–V_ds) output curve at 80 K. (c) The drain source current-drain source voltage (I_ds–V_tg) transfer curve at 80 K (V_ds = 0.01 V). (d) The drain source current-gate source voltage (I_ds–V_tg) transfer curve at 80 K with a back-gate voltage of 90 V (V_ds = 0.01 V). (e) Top gate transfer curves at 15 K with back-gate voltage of 90 V, for bias voltages of 0.1 V and 0.01 V. (f) The drain source current-gate source voltage (I_ds–V_tg) transfer characteristic curve at 15 K with back-gate voltage varying from -40 V to 90 V (V_ds = 0.01 V). (g) The dual-gate modulation dispersion diagram at 15 K (V_ds = 0.01 V), the inset shows the corresponding on/off ratio. (h) The dual-gate modulation dispersion diagram at 15 K V_ds = 0.01 V), the inset shows the corresponding on/off ratio. (i) Maximum on/off ratio of the device under dual-gate modulation at different bias voltages.

作者简介

赵蓓，东南大学青年首席教授/博士生导师。国家优秀青年基金获得者，至善学者(A类)，小米学者，院长助理。主要研究方向为二维半导体的制备与集成器件。以第一作者/通讯作者身份在Nature，Science，Nat. Commun. J. Am. Chem. Soc.，Adv. Mater，Nano lett.，ACS Nano等杂志发表论文20余篇，申请中国发明专利10项，入选首批江苏青年科技人才“U35培育”对象，获得湖南省优秀毕业生，湖南省优秀毕业论文，东南大学青年五四奖章。

秦石乔，国防科技大学前沿交叉学科学院教授。主要研究方向为碳基半导体、二维半导体以及超宽禁带半导体等新型信息材料与器件，主持基础加强重点项目、国家自然科学基金及其它项目多项，以第一作者/通讯作者身份在Light: Science & Applications，Nat. Commun.，Adv. Mater.，Nano lett. 等期刊上发表论文100余篇。

周珺，国防科技大学前沿交叉学科学院讲师。主要研究方向为新型低维半导体材料制备与红外光电子器件，主持国家自然科学基金及其它项目多项，以第一作者/通讯作者身份在Nat. Commun.，Nano lett.，Nanophotonics，Ceram. Int.等期刊上发表论文9篇，申请中国发明专利3项。

卫月华，国防科技大学前沿交叉学科学院博士后。主要研究方向二维半导体材料与器件，主持国家自然科学基金和湖南省自然科学基金，以第一作者/通讯作者在Nano research，Acs Applied Materials Interfaces，Carbon等期刊发表论文20余篇。

文章信息

Wei Y, Li X, Zhou J, et al. Ultraclean CrOCl/bilayer graphene heterointerfaces enable enhanced electrical modulation. Nano Research, 2026, 19(8): 94908726. https://doi.org/10.26599/NR.2026.94908726