高响应度光电检测器件石墨烯-MoS_(2)垂直异质结的制备

Preparation of Graphene-MoS Vertical Heterojunction for High-Responsivity Photodetectors

石墨烯(Gr)及其他类石墨烯的二维(2D)材料,包括六方氮化硼(h-BN)、过渡金属硫族化合物(TMDCs)等,自发现以来便以其独特的物理性质受到了研究人员的青睐。由这些二维层状材料相互堆叠形成的范德瓦尔斯异质结(vdW)因具有很多优异的性质而成为最近的研究热点。本课题组首先制备了大面积、高质量的单层石墨烯及二硫化钼(MoS_(2)),然后将石墨烯薄膜利用光刻及等离子体刻蚀技术制作成石墨烯条带,最后将MoS_(2)转移至石墨烯条带上构成石墨烯-MoS_(2)垂直异质结(Gr-MoS_(2))。测试后发现,基于Gr-MoS_(2)垂直异质结的光电探测器的光电流为单层MoS_(2)器件的250倍,光响应度为单层MoS_(2)器件的750倍。光电性能的提高证明了这种由石墨烯和MoS_(2)堆叠而成的异质结在将来的光电器件及光电子集成电路中具有广阔的应用前景。

Graphene(Gr) and other Gr-like two-dimensional(2 D) materials, including hexagonal boron nitride and transition metal chalcogenides, have been widely investigated by researchers owing to their unique physical properties. Accordingly, the van der Waals heterojunctions formed by stacking these 2 D layered materials have become a research hotspot because of their unique and excellent physical properties. Here, a large-area and highquality single-layer Gr film and a molybdenum disulfide(MoS_(2)) monolayer were synthesized. The Gr film was patterned into microstrips using photolithography and plasma etching techniques. Finally, the MoS_(2) monolayer was transferred onto the Gr strips to form the Gr-MoS_(2) vertical heterojunction. Compared with that of the photodetectors based on the MoS_(2) monolayer, the performance of the photodetectors based on the Gr-MoS_(2) vertical heterojunctions significantly increase. The photocurrent and photoresponsivity of the photodetector based on the Gr-MoS_(2) vertical heterojunction are 250 and 750 times those of the MoS_(2) monolayer, respectively. The improved photoelectric performance proves that this heterojunction formed by stacking Gr and MoS_(2) has broad application prospects in future optoelectronic devices and optoelectronic integrated circuits.