Cui Fangfang, Zhao Xiaoxu, Tang Bin, Zhu Lijie, Huan Yahuan, Chen Qing, Liu Zheng, Zhang Yanfeng
School of Materials Science and Engineering, Peking University, Beijing, 100871, P. R. China.
School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
Small. 2022 Jan;18(4):e2105744. doi: 10.1002/smll.202105744. Epub 2021 Nov 27.
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 Cr S vertical stacks with varied thicknesses are achieved via a one-step chemical vapor deposition (CVD) method route. Various types of 2D Cr S lateral homojunctions are thus naturally evolved, that is, p -ambipolar/n, p/ambipolar, ambipolar/n, and n -ambipolar/n junctions, allowing the integration of diverse conduction polarities in single Cr S homojunctions. Significantly, on-state current density and field-effect mobility of the thinner 2D Cr S flakes stacked below are detected to be ≈5 and ≈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.
为了拓展二维过渡金属二硫属化物（TMDCs）的应用，在同一母体材料中集成具有不同导电极性的功能器件是一个非常有前景的方向。改善金属 - 半导体界面处的接触问题也具有根本重要性。为了同时实现这些目标，通过一步化学气相沉积（CVD）方法路线制备了具有不同厚度的阶梯状CrS垂直堆叠结构。由此自然形成了各种类型的二维CrS横向同质结，即p - 双极/n、p/双极、双极/n和n - 双极/n结，从而能够在单个CrS同质结中集成不同的导电极性。值得注意的是，检测发现堆叠在下方的较薄二维CrS薄片在横向同质结中的导通态电流密度和场效应迁移率分别提高了约5倍和约6倍。这项工作应为设计结构更简单的二维功能器件（例如多极场效应晶体管、光电探测器和逆变器）提供思路，并为优化二维材料相关器件的电学性能提供基础参考。
