A sensitive humidity sensor at low pressure with SnO2 QDs

The humidity sensor working at low pressure has importance in fruit processing industries, space applications, and vacuum coatings. So, it is imperative to develop a sensor to measure very low levels of humidity in a vacuum domain. In the present work, a resistive humidity sensor made of SnO2 Quantu...

Full description

Saved in:
Bibliographic Details
Published in:Sensors and actuators. A. Physical. 2022-10, Vol.346, p.113835, Article 113835
Main Authors: Pan, Sourav, Gayathri, G., Reshma, T.S., Mangamma, G., Prasad, Arun K., Das, A.
Format: Article
Language:English
Subjects:
Atmospheric pressure
Humidity
Hydroxyl groups
Low pressure
Moisture effects
Quantum dots
Resistive humidity sensor
Room temperature
Sensitive at low pressure
Sensors
Space applications
Tin dioxide
Vacuum technology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The humidity sensor working at low pressure has importance in fruit processing industries, space applications, and vacuum coatings. So, it is imperative to develop a sensor to measure very low levels of humidity in a vacuum domain. In the present work, a resistive humidity sensor made of SnO2 Quantum Dots(QDs) is demonstrated. The huge surface area (160 m2/g) of QDs provides plenty of oxygen vacancies at the surfaces which help to absorb moisture even at a low pressure of ~5 mbar starting from the atmospheric pressure. These QDs characterized by XRD, TEM, and optical spectroscopic techniques reveal structural details including the presence of vacancies. The performance of the QDs sensor due to the humidity effect is further proved by flow dry N2 flow. The role of surface hydroxyl groups and their tie-in with RH sensing with high reproducibility performance under vacuum are exclusively highlighted for the first time with SnO2 QDs at room temperature. [Display omitted] •Surfactant free synthesis of SnO2 quantum dots.•Huge specific area and surface defects creation for adsorption of moisture.•Room temperature humidity sensor performing even at low pressure of ~ 5 mbar.•Spectroscopic evidences of surface hydroxyl and H+ mediated resistive mechanism for humidity sensor.
ISSN:0924-4247
1873-3069
DOI:10.1016/j.sna.2022.113835