Despite intensive studies on van der Waals heterostructures based on two-dimensional layered materials, isotype vdW heterojunctions, which consist of two different semiconductors with the same majority carrier, have received little attention. We demonstrate an n–n isotype field-effect heterojunction device composed of multilayer moly ditelluride (MoTe₂) and tin disulfide (SnS₂). The carrier transport flowing through the n-MoTe₂/n-SnS₂ heterojunction exhibits a clear rectifying behavior exceeding 10³, even at a moderate source–drain voltage of 1 V in ambient environment. Owing to the large band offsets between the two materials, a potential barrier exceeding ~1 eV is formed, which is verified by comparing a numerical solution of Poisson’s equation and experimental data. In contrast to the conventional p–n heterostructure operating by diffusion of the minority carrier, we identify the carrier transport is governed by the majority carrier via the thermionic emission and tunneling-mediated process through the potential barrier. Furthermore, the gate voltage can completely turn off the device and even enhance the rectification. A ternary inverter based on the isotype MoTe₂/SnS₂ heterojunction and a SnS₂ channel transistor is demonstrated for potential multivalued logic applications. Our results suggest that the isotype vdW heterojunction will become an able candidate for electronic or optoelectronic devices after suitable band engineering and design optimization.

尽管对基于二维分层材料的范德华异质结构进行了深入研究，但是同型vdW异质结由两种具有相同多数载流子的不同半导体组成，却鲜有受到关注。我们演示了由多层二碲化钼（MoTe ₂）和二硫化锡（SnS ₂）组成的n–n型同型场效应异质结器件。流过n-MoTe ₂ / n-SnS ₂异质结的载流子传输具有清晰的整流行为，超过10 ³，即使在周围环境中为1 V的中等源漏电压时也是如此。由于两种材料之间的带隙较大，因此形成了超过〜1 eV的势垒，这可以通过比较泊松方程的数值解和实验数据来验证。与通过少数载流子扩散操作的常规p–n异质结构相反，我们确定载流子的传输受多数载流子通过热电子发射和通过势垒的隧穿介导过程控制。此外，栅极电压可以完全关闭器件，甚至可以增强整流能力。基于同型MoTe ₂ / SnS ₂异质结和SnS _2的三元逆变器通道晶体管被证明可用于潜在的多值逻辑应用。我们的结果表明，经过适当的频段工程和设计优化后，同型vdW异质结将成为电子或光电设备的可靠候选者。