Optical Trapping of Few‐Layered Materials on Solid Substrates for In Situ and Dynamic Fabrication.

The performances of few‐layered (FL) material‐based devices are usually fixed after fabrication and difficult to be further dynamically tuned. As the thickness approaches the atomic scale, moving FL materials on solid substrates is challenging due to the substantial increase in interfacial friction and simultaneous decrease in stiffness. Here, believed to be the first, optical trapping of FL materials on dry solid substrates is demonstrated, with attractive advantages of ultralow excitation power (µW level), high precision, and wear‐free. The trapping mechanism relies on photothermal shock‐induced thermal gradient force traps. Precise motion control including translation and rotation is achieved, with step resolutions of ≈0.15 nm and ≈1.6 × 10−3 degrees per laser pulse, respectively. Direct locomotion of FL materials with a minimal thickness of 2.5 nm and indirect locomotion of tri‐layers MoS2 (≈1.9 nm thickness) by optically dragging multilayered sections are demonstrated. Furthermore, in situ construction of homo‐ and heterostructures and dynamic modulation of nanowire lasing spectra are showcased. This study will facilitate in situ fabrication of nanoelectronic/photonic devices with both structures and performances dynamically tuned. [ABSTRACT FROM AUTHOR]