Interlayer coupling and electric field controllable Schottky barriers and contact types in graphene/PbI2 heterostructures
Interlayer coupling and electric field controllable Schottky barriers and contact types in graphene/PbI2 heterostructures
复制标题
DOI：
10.1103/physrevb.101.235419
复制
发表时间：
2020-06-08
影响因子：
3.7
通讯作者：
Vu, Tuan V.
中科院分区：
文献类型：
--
作者：
Nguyen, Chuong, V;Idrees, M.;Vu, Tuan V.
通过将石墨烯放置在其他二维半导体材料上而创建的范德华异质结构已成为增强二维（2D）材料物理性能和扩展可能应用的有效策略。受最近实验中成功合成石墨烯/PbI2 异质结构的启发 [Nat.交流。 11, 823 (2020)]，这里我们利用第一性原理计算来构建和研究石墨烯/PbI2异质结构的电子性质和界面特性。我们发现界面处产生的弱力使异质结构保持稳定，并保持石墨烯和 PbI2 单层的固有特性。在平衡层间距离为 3.48 A 时，石墨烯/PbI2 异质结构形成 n 型肖特基接触。更有趣的是，石墨烯/PbI2异质结构中的肖特基势垒高度和接触类型可以通过电场和层间耦合来调节。通过施加电场或调节层间距离，石墨烯/PbI2异质结构可以从n型肖特基接触转变为p型接触或欧姆接触。石墨烯/PbI2异质结构中的可控电子特性和接触类型使其成为设计和提高高效肖特基纳米器件性能的有希望的候选者。
Van der Waals heterostructures, created by putting graphene on other two-dimensional semiconducting materials, have become an effective strategy to enhance the physical properties and extend the possible applications of two-dimensional (2D) materials. Motivated by the successful synthesis of a graphene/PbI2 heterostructure in a recent experiment [Nat. Commun. 11, 823 (2020)], here we use first-principles calculations to construct and investigate the electronic properties and interface characteristics of graphene/PbI2 heterostructure. We find that the weak forces occurring at the interface keep heterostructures stable and maintain the intrinsic properties of the constituent graphene and PbI2 monolayers. At the equilibrium interlayer distance of 3.48 A, the graphene/PbI2 heterostructure forms an n-type Schottky contact. More interestingly, the Schottky barrier height and contact types in the graphene/PbI2 heterostructure can be adjusted by electric field and interlayer coupling. The graphene/PbI2 heterostructure can transform from a n-type Schottky contact to a p-type one or to Ohmic contact by applying electric field or by adjusting interlayer distance. The controllable electronic properties and contact types in graphene/PbI2 heterostructure make it a promising candidate for designing and improving the performance of high-efficiency Schottky nanodevices.