Synthesis, Characterization, and Typical Application of Nitrogen‐Doped MoS2 Nanosheets Based on Pulsed Laser Ablation in Liquid Nitrogen

Abstract

Molybdenum disulfide nanosheets (MoS2 NSs) are synthesized via pulsed laser ablation of MoS2 target in liquid nitrogen (LN2) using the Q‐switched Nd:YAG (Nd:Y3Al5O12) laser. Not only LN2 facilitates the condensation of the laser‐induced plasma plume to produce MoS2 NSs alongside main by‐products (namely, MoS2 quantum dots (QDs)), but also provides an optimum condition for nitrogen‐doped MoS2 (N‐MoS2) synthesis as a p‐type semiconductor. The structural, optical, and chemical properties of NSs are investigated using various electron microscopic instruments and spectrometers. These attest to the formation of suspension MoS2 NSs with a few‐layer structure and rather large lateral size. MoS2 NSs enjoy extra chemical components such as Mo–N bonding. Furthermore, photoluminescence (PL) spectroscopy reveals exciton and trion peaks as the evidence of p‐type property. Subsequently, the Hall effect verifies the p‐type property of N‐MoS2 NSs. By making use of the spin coating, the N‐MoS2 diaphragm has been fabricated; then, it is mounted on the Fabry–Pérot interferometer (FPI) assembly using the fishing method. Thus, N‐MoS2 in FPI acts as a sensitive component of the acoustic optical fiber sensor. The diaphragm operates as ultrasensitive membrane to detect acoustic waves enhancing the sensitivity up to 20% mainly due to the smaller Young's modulus.