Aerosol-Printed MoS<sub>2</sub> Ink as a High Sensitivity Humidity Sensor
Neuma das Mercês Pereira, Natália P. Rezende, Thiago Henrique Rodrigues da Cunha, Ana Paula Moreira Barboza, Glaura G. Silva, Daniel Lippross, Bernardo R. A. Neves, Hélio Chacham, André S. Ferlauto, Rodrigo G. Lacerda
Abstract
High Resolution Image Download MS PowerPoint Slide Molybdenum disulfide (MoS 2 ) is attractive for use in next-generation nanoelectronic devices and exhibits great potential for humidity sensing applications. Herein, MoS 2 ink was successfully prepared via a simple exfoliation method by sonication. The structural and surface morphology of a deposited ink film was analyzed by scanning electron microscopy (SEM), Raman spectroscopy, and atomic force microscopy (AFM). The aerosol-printed MoS 2 ink sensor has high sensitivity, with a conductivity increase by 6 orders of magnitude upon relative humidity increase from 10 to 95% at room temperature. The sensor also has fast response/recovery times and excellent repeatability. Possible mechanisms for the water-induced conductivity increase are discussed. An analytical model that encompasses two ionic conduction regimes, with a percolation transition to an insulating state below a low humidity threshold, describes the sensor response successfully. In conclusion, our work provides a low-cost and straightforward strategy for fabricating a high-performance humidity sensor and fundamental insights into the sensing mechanism.