Binary-ternary transition metal chalcogenides interlayer coupling in van der Waals type-II heterostructure for visible-infrared photodetector with efficient suppression dark currents
Binary-ternary transition metal chalcogenides interlayer coupling in van der Waals type-II heterostructure for visible-infrared photodetector with efficient suppression dark currents
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DOI：
10.1007/s12274-021-3790-4
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发表时间：
2021-09
期刊：
影响因子：
9.9
通讯作者：
Guoliang Xu;Danmin Liu;Songyu Li;Yi Wu;Zhenlu Zhang;Shaobo Wang;Zikun Huang;Yongzhe Zhang
中科院分区：
文献类型：
--
作者：
Guoliang Xu;Danmin Liu;Songyu Li;Yi Wu;Zhenlu Zhang;Shaobo Wang;Zikun Huang;Yongzhe Zhang
三元二维（2D）材料根据其组成、结构和厚度表现出不同的物理性质。通过与具有类似结构的其他二元材料形成异质结构，这些三元2D材料可以有许多潜在的应用。本文报道了用X射线衍射、透射电子显微镜和电子密度分布计算等方法研究少层CrPS_4结构的结果。我们还展示了CrPS 4/MoS 2异质双层膜的一个新应用：室温下具有II型交错带排列的可见-红外光电探测器。异质结构对红外光的响应是由于强的层间耦合导致结区的能量间隔减小。由于各个组件的固有带隙决定波长，因此能量间隔的减小允许更好地检测具有较长波长的光。我们使用光致发光（PL）光谱、Kelvin探针力显微镜（KPFM）和电输运测量来验证CrPS 4/MoS 2异质结构之间的光致电荷分离。在正向偏压下，该器件作为一个高灵敏度的光电探测器，因为波长相关的光电流测量实现了从532至1,450 nm波长的光激发的观察。此外，层间激子引起的光电流在1，095 nm波长处达到约1.2 nA。我们对CrPS 4/MoS 2异质结构中强层间耦合的研究，将有助于进一步理解二元-三元过渡金属硫族化合物异质结构的基本物理机制，并为其在可见-红外器件中的潜在应用铺平道路。
Ternary two-dimentional (2D) materials exhibit diverse physical properties depending on their composition, structure, and thickness. Through forming heterostructures with other binary materials that show similar structure, there can be numerous potential applications of these ternary 2D materials. In this work, we reported the structure of few-layer CrPS4by X-ray diffraction, transmission electron microscope, and electron-density distribution calculation. We also demonstrated a new application of the CrPS4/MoS2heterobilayer: visible-infrared photodetectors with type-II staggered band alignment at room temperature. The response of the heterostructure to infrared light results from a strong interlayer coupling that reduces the energy interval in the junction area. Since the intrinsic bandgap of individual components determines wavelengths, the decrease in energy interval allows better detection of light that has a longer wavelength. We used photoluminescence (PL) spectroscopy, Kelvin probe force microscopy (KPFM) under illumination, and electrical transport measurements to verify the photoinduced charge separation between the CrPS4/MoS2heterostructures. At forward bias, the device functioned as a highly sensitive photodetector, as the wavelength-dependent photocurrent measurement achieved the observation of optical excitation from 532 to 1,450 nm wavelength. Moreover, the photocurrent caused by interlayer exciton reached around 1.2 nA at 1,095 nm wavelength. Our demonstration of the strong interlayer coupling in the CrPS4/MoS2heterostructure may further the understanding of the essential physics behind binary-ternary transition metal chalcogenides heterostructure and pave a way for their potential applications in visible-infrared devices.