Excimer Laser-Enabled Photochemical Synthesis of WS2 Thin Films

Tungsten disulfide (WS 2 ), a representative transition metal dichalcogenide (TMDC), has emerged as a pivotal material for logic, optoelectronic, and flexible electronics owing to its exceptional properties. However, cumbersome synthesis protocols and multi-step fabrication processes severely hinder its practical implementations. Herein, we report a direct, rapid, and scalable approach for synthesizing large-area WS 2 thin films utilizing an excimer laser (λ= 248 nm). By employing a machine learning (ML) framework to optimize the laser processing parameters, the controllable synthesis of WS 2 is achieved with negligible thermal accumulation. Furthermore, we successfully fabricated WS 2 -based field-effect transistors (FETs) and flexible strain sensors. Notably, the FETs exhibit a remarkable I on /I off current ratio of 10 6 and an electron mobility of 6.72 cm 2 /V∙s. This methodology not only facilitates the large-area synthesis and device integration of WS 2 but also presents a versatile pathway for developing micro/nano-devices based on a broad spectrum of TMDCs and other functional materials. Download: Download high-res image (221KB) Download: Download full-size image