Rapid In-Situ Synthesis and Patterning of Edge-Unsaturated MoS₂ by Femtosecond Laser-Induced Photo-Chemical Reaction

Abstract

Molybdenum disulfide (MoS2) is a representative transition metal sulfide that is widely used in gas and biological detection, energy storage, and integrated electronic devices due to its unique optoelectrical and chemical characteristics. To advance toward the miniaturization and on-chip integration of functional devices, it is strategically important to develop a high-precision and cost-effective method for the synthesis and integration of MoS2 patterns and functional devices. Traditional methods require multiple steps and time-consuming processes such as material synthesis, transfer, and photolithography to fabricate MoS2 patterns at the desired region on the substrate, significantly increasing the difficulty of manufacturing micro/nanodevices. In this work, we propose a single-step femtosecond laser-induced photochemical method which can realize the fabrication of arbitrary two-dimensional edge-unsaturated MoS2 patterns with high efficiency in microscale. Based on this method, MoS2 can be synthesized at a rate of 150 μm/s, 2 orders of magnitude faster than existing laser-based thermal decomposition methods without sacrificing the resolution and quality. The morphology and roughness of the MoS2 pattern can be controlled by adjusting the laser parameters. Furthermore, the femtosecond laser direct writing (FLDW) method was used to fabricate microscale MoS2-based gas detectors that can detect a variety of toxic gases with high sensitivity up to 0.5 ppm at room temperature. This FLDW method is not only applicable to the fabrication of high-precision MoS2 patterns and integrated functional devices, it also provides an effective route for the development of other micro/nanodevices based on a broad range of transition metal sulfides and other functional materials.

Amorphous mesoporous carbon nanomaterials converted from waste paper via nanosecond laser photochemical synthesis

“…As exemplified in Figures 3a and 3b, the jointed picture shows a 20 mm range carbon-patterned area, where LCM uses digital splicing technology for a macroscopic view. Therefore, laser synthesis provides more opportunities for using amorphous carbon as functional coating, water splitting, and other large-area applications [19] . To evaluate the crystallization and specific morphologies of amorphous carbon nanomaterials by shifted photon energy, the high-resolution transmission electron microscope (HRTEM) is conducted to analyze crystal degree and diffraction features with FFT calculation.…”

Laser-assisted synthesis of two-dimensional transition metal dichalcogenides: a mini review

“…(A) Flow diagram of direct laser writing, a method for the laser-directed synthesis of MoS 2 on the SiO 2 /Si wafer ( Xu et al, 2021a ) (Copyright 2021, Elsevier). (B) Schematic of MoS 2 synthesized by femtosecond laser ( Xu et al, 2022 ) (Copyright 2022, American Chemical Society). (C) Schematic of the layer synthesis of MoS 2 –WS 2 heterostructure ( Park et al, 2020a ) (Copyright 2020, American Chemical Society).…”

Cellulose‐Derived Wearable Carbon Nanoflake Sensors Customized by Semiconductor Laser Photochemistry

“…To date, multitudinous semiconductors, electrical circuits, sensors, robotics, and interfaces have sprung up in the last decade using ultrafast laser ablation, two‐photon polymerization, [ 1 ] lifting off, [ 3 ] or photochemical reduction on hard and brittle wafers. [ 4 ] Unfortunately, despite the merits of volume reduction/function controllability, laser‐based synthesis remains stifled for wearable applications. In the world of electronics, most electric products rely on bio‐incompatible metal alloys or oxides, require tedious processing (annealing, etching, photolithography, or so on), and are constrained to rigid substrates.…”

“…The green, facile, digitalized laser synthesis, [1] a forerunner method for low-dimensional high-performance materials, is silently developing our high-tech products in multi fields ever since. [2][3][4][5] Photons from laser resonant cavities hit the precursors, causing spatially-confined chemical reactions driven by light energy different from hydrothermal/electrical chemistry or chemical vapor deposition. To date, multitudinous semiconductors, electrical circuits, sensors, robotics, and interfaces have sprung up in the last decade using ultrafast laser ablation, two-photon polymerization, [1] lifting off, [3] or photochemical reduction on hard and brittle wafers.…”

“…Hereby, in our scenario, combining the low-cost, degradable cellulose-based papers with a noncontact laser synthesis will eliminate the tedious preparation of precursor materials. The sophisticated chemical processes were simplified, and laser synthesis maximizes the digitalized advantages [22,23] of computer-assisted fabrication, [1][2][3][4]22,23] garnering considerable interest in developing wearable electronics.…”