Capacitive and resistive response of humidity sensors based on graphene decorated by PMMA and silver nanoparticles

SENSORS AND ACTUATORS B-CHEMICAL

卷:267

Article

Rahim, Ishrat¹  Shah, Mutabar¹  Khan, Afzal¹  Luo, Jingting²  Zhong, Aihua²  Li, Min²  Ahmed, Rashid³  Li, Honglang⁴  Wei, Qiuping⁵  Fu, Yongqing⁶ 

[1] Univ Peshawar, Dept Phys, Peshawar 25000, Pakistan

[2] Shenzhen Univ, Coll Phys & Energy, Shenzhen Key Lab Adv Thin Films & Applicat, Shenzhen 518060, Peoples R China

[3] Univ Teknol Malaysia, Dept Phys, Fac Sci, Utm Skudai 81310, Johor, Malaysia

[4] Chinese Acad Sci, Inst Acoust, Beijing 100190, Peoples R China

[5] Cent South Univ, State Key Lab Powder Met, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China

[6] Northumbria Univ, Fac Engn & Environm, Newcastle Upon Tyne NE1 8ST, Tyne & Wear, England

关键词: Humidity sensors;    Graphene;    Thin film;    Response/recovery;    Band gap;   

DOI  :  10.1016/j.snb.2018.03.069

来源: Elsevier

【 摘 要 】

In this paper, we reported comparative study of the humidity characteristics of graphene/silver nanoparticles composite (Gr-AgNps) and graphene/silver nanoparticles/PMMA composite (Gr-AgNps-PMMA) based efficient humidity sensors. Aqueous solution of Gr-AgNps and Gr-AgNps-PMMA was drop casted over interdigitated copper electrodes with 50 pin gap embedded in the substrates in dust free environment. The band gap obtained from the IJV-vis spectra for Gr-AgNps and Gr-AgNps-PMMA based humidity sensors was 4.7 and 4.1 eV respectively. The capacitive and resistive humidity response was studied using LCR meter (GW Instek817). Apparent increase in capacitance was observed (100-10,000 nF) with the increase in the humidity percentage (30-95%RH) at lower frequencies for both the sensors. Resistance of the sensors dropped to zero as the humidity level is increased from 30 to 95%RH in the chamber. The devices were tested for real time stability and for fast response/recovery time. Both the devices showed an excellent stability and response by recording their resistance and capacitance respectively. A lagging of RH decreasing response from RH increasing response was observed at 500 Hz frequency for both the sensors depicted from the hysteresis curve. The humidity response of Gr-AgNps was comparatively better than that of the Gr-AgNps-PMMA based humidity sensors. (C) 2018 Elsevier B.V. All rights reserved.

【 授权许可】

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