Bolstering functionality in multilayer and bilayer WS2 via focused laser micro-engraving

作     者：Si Min CHAN Eng Tuan POH Jin Feng LEONG Kuan Eng Johnson GOH Chorng Haur SOW Si Min CHAN;Eng Tuan POH;Jin Feng LEONG;Kuan Eng Johnson GOH;Chorng Haur SOW

作者机构：Department of PhysicsNational University of Singapore Institute of Materials Research and EngineeringAgency for ScienceTechnology and Research (A~*STAR) Division of Physics and Applied PhysicsSchool of Physical and Mathematical SciencesNanyang Technological University 

出 版 物：《Science China(Information Sciences)》 (中国科学:信息科学(英文版))

年 卷 期：2023年第66卷第6期

页      面：94-101页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：supported by Agency for Science, Technology and Research (A~*STAR) (Grant No. 1527000016) support from Agency for Science, Technology and Research (Grant No. #21709) Singapore National Research Foundation (Grant No. CRP21-2018-0001) 

主　　题：WS$_2$ monolayer micro-patterning focused laser sonication lift-off 

摘      要：Laser thinning of multilayer transition metal dichalcogenide(TMD)crystals has long been explored for its potential to produce localized domains of optically functional monolayers. Despite the high spatial control and resolution of the laser, the range of appropriate applications for these laser-thinned domains is still limited by the peripheral regions of unaltered thick multilayers. Herein, we report a newfound property of the laser-thinned regions to adhere strongly to the underlying substrate when lasered down to the monolayer limit. Upon a brief sonication in various solvents, the surrounding pristine multilayers can be lifted off, solely leaving behind the post-lasered monolayer patterns. Coupled with the flexible maneuver of the laser, various monolayer designs can be achieved, including micro-antenna, waveguide, and electrode geometries with lateral line widths at 1.5 μm resolution. Furthermore, we also detail the optical properties of the monolayers obtained from laser thinning, with those acquired from multilayers containing more defectbound excitons, whereas those lasered from bilayers presenting a trion-dominated profile similar to as-grown monolayers. Together, these findings allow for faster and more efficient multilayer removal and areal shaping of optically active monolayer domains, in comparison to multistep and complex standard lithographic etching(lithography–etch–develop)procedures.