Direct laser ablation of 2D material films for fabricating multi-functional flexible and transparent devices

Abstract: We present a scalable method for direct patterning of graphite and transition metal dichalcogenide (TMD) films on polycarbonate (PC) and other transparent substrates using fiber laser ablation. This process facilitates the fabrication of various functional devices, including strain gauges, supercapacitors, and photodetector arrays, without the need for photolithography or solvents, thereby simplifying device production and enhancing environmental sustainability. Utilizing roll-to-roll mechanical exfoliation, homogeneous nanosheet films are created and then patterned with a laser engraving system. Electrical and optical characterization confirms that the laser-processed films maintain their crystallinity, with no observable damage to the underlying substrate. We demonstrate the scalability of this approach by constructing a WSe2/graphite photodetector array on PC, which exhibits high sensitivity, low noise, and uniform photocurrent response across its active channels. As a proof-of-concept, this array is used as an image sensor to capture light patterns, showcasing its potential for flexible and semi-transparent imaging applications. These findings open up new avenues for incorporating all-van der Waals devices into wearable electronics, optoelectronics, and imaging technologies.