Zou Zixing, Li Dong, Liang Junwu, Zhang Xuehong, Liu Huawei, Zhu Chenguang, Yang Xin, Li Lihui, Zheng Biyuan, Sun Xingxia, Zeng Zhouxiaosong, Yi Jiali, Zhuang Xiujuan, Wang Xiao, Pan Anlian
Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, Hunan 410082, P. R. China.
School Physics and Telecommunication Engineering, Yulin Normal University, Yulin, Guangxi 537000, P. R. China.
Nanoscale. 2020 Mar 19;12(11):6480-6488. doi: 10.1039/c9nr10387b.
van der Waals (vdWs) heterostructures, combining different two-dimensional (2D) layered materials with diverse properties, have been demonstrated to be a very promising platform to explore a new physical phenomenon and realize various potential applications in atomically thin electronic and optoelectronic devices. Here, we report the controlled growth of vertically stacked β-In2Se3/MoS2 vdWs heterostructures (despite the existence of large lattice mismatching ∼29%) through a typical two-step chemical vapor deposition (CVD) method. The crystal structure of the achieved heterostructures is characterized by transmission electron microscopy, where evident Moiré patterns are observed, indicating well-aligned lattice orientation. Strong photoluminescence quenching is obeserved in the heterostructure, revealing effective interlayer charge transfer at the interface. Electrical devices are further constructed based on the achieved heterostructures, which have a high on/off ratio and a typical rectifying behavior. Upon laser irradiation, the devices show excellent photosensing properties. A high responsivity of 4.47 A W-1 and a detectivity of 1.07 × 109 Jones are obtained under 450 nm laser illumination with a bias voltage of 1 V, which are much better than those of heterostructures grown via CVD. Most significantly, the detection range can be extended to near-infrared due to the relatively small bandgap nature of β-In2Se3. With 830 nm laser illumination, the devices also show distinct photoresponses with fast response speed even when operating at room temperature. The high-quality β-In2Se3/MoS2 heterostructures broaden the family of the 2D layered heterostructure system and should have significant potential applications in high-performance broadband photodetectors.
范德华（vdWs）异质结构将具有不同性质的不同二维（2D）层状材料结合在一起，已被证明是探索新物理现象和实现原子级薄电子及光电器件中各种潜在应用的非常有前景的平台。在此，我们报告了通过典型的两步化学气相沉积（CVD）方法可控生长垂直堆叠的β-In2Se3/MoS2 vdWs异质结构（尽管存在约29%的大晶格失配）。所制备异质结构的晶体结构通过透射电子显微镜进行表征，在其中观察到明显的莫尔条纹，表明晶格取向良好对齐。在异质结构中观察到强烈的光致发光猝灭，揭示了界面处有效的层间电荷转移。基于所制备的异质结构进一步构建了电子器件，其具有高开关比和典型的整流行为。在激光照射下，器件表现出优异的光传感特性。在450 nm激光照射和1 V偏置电压下，获得了4.47 A W-1的高响应度和1.07×109琼斯的探测率，这比通过CVD生长的异质结构要好得多。最显著的是，由于β-In2Se3相对较小的带隙性质，检测范围可以扩展到近红外。在830 nm激光照射下，即使在室温下操作，器件也表现出具有快速响应速度的明显光响应。高质量的β-In2Se3/MoS2异质结构拓宽了二维层状异质结构系统的家族，并且在高性能宽带光电探测器中应具有重要的潜在应用。
