Geometry-Derived Asymmetric Schottky Contacts Based on Chemical Vapor Deposited MoS2

The physical and electronic asymmetry of metal–semiconductor–metal (MSM) can be regarded as a unique feature, which may be unconsciously introduced when constructing MSM heterostructures and devices. Here, we reveal asymmetrical Schottky contacts derived from the triangular geometry of chemical vapor deposited (CVD) MoS2 with different Ti/Au electrode areas. A significant rectification can be induced in such an asymmetrical Schottky contact of MSM, with a modulated rectification ratio over 104 under external gating and laser illumination. The Schottky barrier (SB) height difference caused by the triangular MoS2 geometry-derived asymmetric contact was then verified through constructing a symmetrical contact of MSM based on the triangular CVD MoS2 with different symmetrical contact areas. The effective SB height difference corresponding to asymmetric contacts was also extracted based on the optimized thermal excitation theory. This work not only presents an intriguing case for the preparation of devices based on CVD 2D materials with particular geometries but also provides a facile method for the design of various device geometries for potential applications in electronics and optoelectronics.