Recognition and Evaporation Monitoring of Micro-Droplet VOCs Based on CVD-Grown Monolayer MoS2 through a Dielectric Screening Effect

Herein, an optical evaporation sensor is achieved based on the photoluminescence (PL) property of monolayer MoS2 through the micro-droplet dielectric screening effect. The emission intensity, full width at half-maximum, photon energy, and intensity ratio of two excitons are related to the dielectric constant of the micro-droplets, which are employed to recognize the kind of liquids. During the evaporation process of volatile organic compound micro-droplets, the collected PL intensity is significantly affected by the refractive index. The theoretical model of a micro-droplet evaporation sensor based on the dielectric screening effect is established and verified by the finite-difference time-domain and the finite-element method. This work processes a fluorescent probe technique for micro-droplet recognition and evaporation monitoring with non-contact, high precision, and miniaturization.

Automated summary

A fluorescence-based evaporation sensor utilizing the photoluminescence property of monolayer MoS2 and the dielectric screening effect of micro-droplets is developed. This sensor can identify different liquids and monitor the evaporation process of micro-droplets.