Electrically tunable two-dimensional heterojunctions for miniaturized near-infrared spectrometers
Wenjie Deng, Zilong Zheng, Jingzhen Li, Rongkun Zhou, Xiaoqing Chen, Dehui� Zhang, Yue Lu, Chongwu Wang, Congya You, Songyu Li, Ling Sun, Yi Wu, Xuhong Li, Boxing An, Zheng Liu, Qi Jie Wang, Xiangfeng Duan, Yongzhe Zhang
Abstract
Miniaturized spectrometers are of considerable interest for their portability. Most designs to date employ a photodetector array with distinct spectral responses or require elaborated integration of micro & nano optic modules, typically with a centimeter-scale footprint. Here, we report a design of a micron-sized near-infrared ultra-miniaturized spectrometer based on two-dimensional van der Waals heterostructure (2D-vdWH). By introducing heavy metal atoms with delocalized electronic orbitals between 2D-vdWHs, we greatly enhance the interlayer coupling and realize electrically tunable infrared photoresponse (1.15 to 1.47 μm). Combining the gate-tunable photoresponse and regression algorithm, we achieve spectral reconstruction and spectral imaging in a device with an active footprint < 10 μm. Considering the ultra-small footprint and simple fabrication process, the 2D-vdWHs with designable bandgap energy and enhanced photoresponse offer an attractive solution for on-chip infrared spectroscopy.