Cui Ruopeng, Li Yi, Zhang Xuefei, Duan Zewen, Zhao Biao, Wan Chunlei
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing, China.
Nat Commun. 2025 Jul 1;16(1):5804. doi: 10.1038/s41467-025-60707-3.
Integrating 2D (semi)metals and semiconductors into atomic-scale Schottky heterojunctions offers a promising pathway for achieving robust charge separation, crucial for microwave absorbers, electromagnetic interference shielding materials, electrocatalysts, photocatalysts, etc. However, conventional bottom-up assembly approaches often encounter challenges of severe agglomeration of 2D components and non-basal contacts due to lattice mismatch, resulting in a suboptimal interfacial density and insufficient charge separation. This study introduces a top-down approach involving the thermal deintercalation of graphene/alkylamine superlattices, leading to the in-situ formation of Schottky heterojunctions between the thermally reduced p-type rGO-alkylamine superlattice phase and entirely deintercalated semimetallic rGO phase (rGO denotes reduced graphene oxide), which can be flexibly tuned by the length of the alkylamines. A spatial network of 2D/2D vertical/lateral Schottky heterojunctions is thus formed with high interfacial density, greatly facilitating charge separation, and thereby strengthening polarization loss while reducing conduction loss. This ensures steady permittivity in the Ku band, maintaining strong absorption under small oblique incidence. Accordingly, a record-high simulated far-field bistatic radar cross-section reduction of 72.68 dB at 1° is attained along with diversified adaptive multifunctionality. This paper provides a groundbreaking avenue realizing spatially distributed atomic-scale 2D/2D Schottky heterojunctions in 2D materials, promoting various related functional materials.
将二维（半）金属和半导体集成到原子尺度的肖特基异质结中，为实现强大的电荷分离提供了一条有前景的途径，这对于微波吸收器、电磁干扰屏蔽材料、电催化剂、光催化剂等至关重要。然而，传统的自下而上组装方法通常会遇到二维组件严重团聚以及由于晶格失配导致的非基面接触的挑战，从而导致界面密度不理想和电荷分离不足。本研究引入了一种自上而下的方法，涉及石墨烯/烷基胺超晶格的热脱嵌，导致在热还原的p型rGO-烷基胺超晶格相和完全脱嵌的半金属rGO相（rGO表示还原氧化石墨烯）之间原位形成肖特基异质结，这可以通过烷基胺的长度灵活调节。由此形成了具有高界面密度的二维/二维垂直/横向肖特基异质结空间网络，极大地促进了电荷分离，从而增强了极化损耗，同时降低了传导损耗。这确保了Ku波段的介电常数稳定，在小角度入射下保持强吸收。因此，在1°时实现了创纪录的72.68 dB的模拟远场双站雷达散射截面缩减以及多样化的自适应多功能性。本文提供了一条开创性的途径，可在二维材料中实现空间分布的原子尺度二维/二维肖特基异质结，推动各种相关功能材料的发展。
