Sorption/desorption hysteresis of thin-film humidity sensors based on graphene oxide and its derivative

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• 作者：Sang-Wook Lee^a ; ^{sangwook@kriss.re.kr" class="auth_mail" title="E-mail the corresponding author} ; ^{ohok1004@snu.ac.kr" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Byung Il Choi^aAuthor Vitae ; Jong Chul Kim^aAuthor Vitae ; Sang-Bong Woo^aAuthor Vitae ; Yong-Gyoo Kim^aAuthor Vitae ; Suyong Kwon^aAuthor Vitae ; Jeseung Yoo^bAuthor Vitae ; Young-Soo Seo^bAuthor Vitae
• 关键词：Graphene oxide ; Humidity ; Sensor ; Hysteresis ; Sorption/desorption
• 刊名：Sensors & Actuators: B. Chemical
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：237
• 期：Complete
• 页码：575-580
• 全文大小：1847 K

文摘

We study the sorption/desorption hysteresis of thin-film humidity sensors using graphene oxide (GO) and amine-modified GO (GO-NH₂) as sensing materials for relative humidity (%RH in unit) based on capacitance and conductance measurements. GO sensors present a lower level of hysteresis-induced errors in both capacitance (3.1 ± 0.5%RH) and conductance (2.2 ± 0.2%RH) measurements in the humidity range from 5%RH to 95%RH at 25 °C, whereas GO-NH₂ sensors show a higher degree of hysteresis, resulting in errors of 5.9 ± 1.0%RH and 7.9 ± 0.4%RH by capacitance and conductance measurements, respectively. We discuss a possible mechanism behind the hysteretic behavior of these sensors based on molecular compositions and their interactions with water molecules by using Fourier transform infrared (FT-IR) spectroscopy and by elevating the experimental temperature, respectively. We find the hysteresis-induced errors present a trade-off relationship with the sensitivity between these sensors, emphasizing the importance of studying the sorption/desorption hysteresis as an essential factor in the development of humidity sensors.