Transfer-Free Growth of Atomically Thin Transition Metal Disulfides Using a Solution Precursor by a Laser Irradiation Process and Their Application in Low-Power Photodetectors

Abstract

Although chemical vapor deposition is the most common method to synthesize transition metal dichalcogenides (TMDs), several obstacles, such as the high annealing temperature restricting the substrates used in the process and the required transfer causing the formation of wrinkles and defects, must be resolved. Here, we present a novel method to grow patternable two-dimensional (2D) transition metal disulfides (MS2) directly underneath a protective coating layer by spin-coating a liquid chalcogen precursor onto the transition metal oxide layer, followed by a laser irradiation annealing process. Two metal sulfides, molybdenum disulfide (MoS2) and tungsten disulfide (WS2), are investigated in this work. Material characterization reveals the diffusion of sulfur into the oxide layer prior to the formation of the MS2. By controlling the sulfur diffusion, we are able to synthesize continuous MS2 layers beneath the top oxide layer, creating a protective coating layer for the newly formed TMD. Air-stable and low-power photosensing devices fabricated on the synthesized 2D WS2 without the need for a further transfer process demonstrate the potential applicability of TMDs generated via a laser irradiation process.

Flexible Transparent and Free‐Standing SiC Nanowires Fabric: Stretchable UV Absorber and Fast‐Response UV‐A Detector

“…The inset of Figure b shows a transient photoresponse. The rise and decay times were both found to be shorter than 30 ms, which is faster than many previously reported semiconductor‐based prototype devices . We examined I ph as a function of incident power intensity at a fixed voltage (5 V) and Figure b shows the dependence in logarithmic coordinates.…”

Recent trends in covalent functionalization of 2D materials

“…Graphene [476][477][478][479][480] and TMDCs [481][482][483] can be synthesized by laser irradiation by local high-temperature heating from the photothermal effect. When the laser power is sufficiently strong to carbonize the precursor before it reacts with oxygen in the air and burns, the carbon-containing material thermally carbonizes and becomes laser-induced graphene (LIG).…”

Nanolasers Based on 2D Materials

“…Similar to graphene, layered TMDs can be mechanically exfoliated to monolayer or few‐layer nanosheets due to the strong in‐plane covalent bonds and weak out‐of‐plane van der Waals bonds. [ 86,87 ] In addition, the chemical vapor deposition (CVD) and chemical solution synthesis techniques provide great promise in preparing large‐area and high‐quality TMDs. [ 88,89 ] In 2018, a molten‐salt‐assisted CVD method was developed and further extended the synthesis categories of TMDs to 47 compounds.…”