High-performance humidity sensor constructed with vertically aligned graphene arrays on silicon Schottky junctions

•Growth of VAGAs on Si, without the post-transfer process for humidity sensor fabrication.•The humidity sensor exhibits fast response and recovery time.•The humidity sensor can be fully-reversible operation by Joule-heating.•The mechanism of humidity detection is confirmed by the SKPM and simulation...

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Bibliographic Details
Published in:Materials letters 2020-10, Vol.277, p.128343, Article 128343
Main Authors: Wang, Hang, Zhao, Menghan, Zhu, Wei, Liu, Zhiduo, Wang, Gang, Tang, Shiwei, Chen, Da, Lee, Jong-Min, Yang, Siwei, Ding, Guqiao
Format: Article
Language:English
Subjects:
Aspect ratio
Carbon materials
Chemical vapor deposition
Electrical properties
Gas sensors
Graphene
Humidity
Humidity sensor
Materials science
Mechanism
Recovery time
Sensor arrays
Silicon substrates
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Summary:•Growth of VAGAs on Si, without the post-transfer process for humidity sensor fabrication.•The humidity sensor exhibits fast response and recovery time.•The humidity sensor can be fully-reversible operation by Joule-heating.•The mechanism of humidity detection is confirmed by the SKPM and simulation. Vertically aligned graphene arrays (VAGAs) are perpendicularly oriented and interconnected by arrangements with high aspect ratios and specific surface areas, promoting the gas molecule adsorption capacity and active surface sensitivity. By taking advantage of plasma-assisted chemical vapor deposition (PACVD), growth of VAGAs on silicon (Si) substrate has been demonstrated. As-grown VAGAs/Si has excellent Schottky junction-based humidity sensing characteristics with fast response and recovery time. Joule-heating dismisses physical absorbed vapor molecules from the vertical arrangement, realizing fully-reversible operation. The mechanism of humidity detection is explored by the scanning Kelvin probe microscopy (SKPM) and finite difference time domain (FDTD) simulation. Our study may promote the advancement of gas sensors.
ISSN:0167-577X
1873-4979
DOI:10.1016/j.matlet.2020.128343