Large-Scale Uniform-Patterned Arrays of Ultrathin All-2D Vertical Stacked Photodetector Devices

The key to unlocking the full potential of two-dimensional (2D) materials in ultrathin opto-electronics is their layer-by-layer integration and the ability to produce them on the wafer scale using traditional industry-compatible technology. Here, we demonstrate a novel stacking method for assembling uniform-patterned periodic 2D arrays into vertical-layered heterostructures. The fabricated heterostructure can serve as photodetectors, with graphene electrodes and transition-metal dichalcogenides as the photo-absorber. All 2D materials used are grown into continuous fil ms with only mono- or bilayer thickness. Each layer is prepatterned into a specific shape on a substrate and then transferred to the device substrate with a ligned precision. In order to achieve long-range alignment across the wafer, interlocking marker pairs are used to help guide the lateral accuracy and reduce rotational error. We show hundreds of identical devices produced with 2D periodic spacing on a 1 cm x 1 cm SiO2/Si substrate, a fundamental prerequisite for future pixelated detectors. Statistics of the photovoltaic performance of the devices are reported, with values that are comparable to devices made by chemical vapor deposition-grown materials. Our work provides pathways for the large-scale fabrication of ultrathin all-2D opto-electronics that form the basis of the future in 2D-pixelated cameras and displays.

Automated summary

The study demonstrates a novel stacking method for assembling uniform-patterned periodic 2D arrays into vertical-layered heterostructures, which can serve as photodetectors. The materials used are grown into continuous films with mono- or bilayer thickness and have photovoltaic performance comparable to those made by chemical vapor deposition-grown materials. This work provides pathways for the large-scale fabrication of ultrathin all-2D opto-electronics for future 2D-pixelated cameras and displays.