Lithography‐Free Site‐Specific Synthesis of Size‐Tailored Platinum Dichalcogenides

Practical optoelectronic application of 2D Pt dichalcogenides faces two crucial challenges: establishing a reliable synthetic route and developing a pertinent patterning technique. A streamlined strategy is proposed for site‐specific and size‐tunable synthesis of Pt dichalcogenides, achieved by pre‐defining of Pt templates via focused ion beam (FIB) combined with selenization or tellurization without requiring lithography processes. The synthetic conditions are optimized by altering reaction temperature, time, and thickness of Pt templates, as verified by comprehensive spectro‐microscopic analysis. The universal applicability of streamlined site‐specific synthesis for Pt dichalcogenides is ascertained, highlighting its potential for visible and NIR photodetection. The PtSe 2 ‐based photodetector exhibits maximized photocurrents of 134 µA at 532 nm and 178 µA at 980 nm, whereas the PtTe 2 ‐based device demonstrates enhanced values of 231 and 382 µA at the respective wavelengths. This approach corroborates an innovative route to resolve prerequisites associated with establishing a reliable synthetic route and developing a pertinent patterning technique.