Epitaxial Growth of Step-Like Cr2S3 Lateral Homojunctions Towards Versatile Conduction Polarities and Enhanced Transistor Performances

For expanding the applications of 2D transition metal dichalcogenides (TMDCs), integrating functional devices with diverse conduction polarities in the same parent material is a very promising direction. Improving the contact issue at the metal-semiconductor interface also holds fundamental significance. To achieve these concurrently, step-like Cr2S3 vertical stacks with varied thicknesses are achieved via a one-step chemical vapor deposition (CVD) method route. Various types of 2D Cr2S3 lateral homojunctions are thus naturally evolved, that is, p(m)-ambipolar/n, p/ambipolar, ambipolar/n, and n(m)-ambipolar/n junctions, allowing the integration of diverse conduction polarities in single Cr2S3 homojunctions. Significantly, on-state current density and field-effect mobility of the thinner 2D Cr2S3 flakes stacked below are detected to be approximate to 5 and approximate to 6 times increased in the lateral homojunctions, respectively. This work should hereby provide insights for designing 2D functional devices with simpler structures, for example, multipolar field-effect transistors, photodetectors, and inverters, and provide fundamental references for optimizing the electrical performances of 2D materials related devices.