Herein, first-principles density functional theory calculations are performed to investigate the interface coupling and electrostatic doping effect in the graphene/LiNbO₃(0001) [denoted as Gr/LNO(0001)] heterostructure. The results show that, in addition to the coupling mechanism of the large ionic–van der Waals interaction, an unusual electrostatic doping, which is in contrast with the polarization compensation mechanism, appears in the Gr/LNO(0001) system: for graphene adsorbed on the thermodynamically preferred ferroelectric LiNbO₃(0001) [denoted as LNO(0001)] positive (Z+) and negative (Z−) surfaces, carriers are of p- and n-type, respectively. Further analysis indicates that the electrostatically doped effect of the graphene layer adsorbed on the LNO(0001) polar surfaces should be determined by the particular band alignment between the LNO(0001) polar surfaces and graphene. Our studies provide theoretical evidence for designing p–n homojunctions in a graphene sheet by engineering the domain structure of the LNO(0001) ferroelectric substrates. Furthermore, the significant change in carrier density caused by the reversal of the ferroelectric polarization direction suggests that the Gr/LNO(0001) system could be a promising platform to explore ferroelectric field-effect transistors.

在此，执行第一性原理密度泛函理论计算以研究石墨烯/LiNbO ₃ (0001) [表示为 Gr/LNO(0001)] 异质结构中的界面耦合和静电掺杂效应。结果表明，除了大离子-范德华相互作用的耦合机制外，在 Gr/LNO(0001) 体系中还出现了与极化补偿机制相反的异常静电掺杂：对于吸附的石墨烯在热力学优选的铁电体 LiNbO ₃ (0001) [表示为 LNO(0001)] 正 (Z+) 和负 (Z-) 表面上，载流子为p - 和n- 类型，分别。进一步分析表明，吸附在 LNO(0001) 极性表面上的石墨烯层的静电掺杂效应应由 LNO(0001) 极性表面和石墨烯之间的特定带排列决定。我们的研究通过设计 LNO(0001) 铁电衬底的畴结构，为在石墨烯片中设计p - n同质结提供了理论依据。此外，由铁电极极化方向反转引起的载流子密度的显着变化表明 Gr/LNO(0001) 系统可能是探索铁电场效应晶体管的有前途的平台。