Superior enhancement of NO₂ gas response using n-p-n transition of carbon nanotubes/SnO₂ nanowires heterojunctions

详细信息    查看全文

• 作者：Quan Thi Minh Nguyet^a ; ^bAuthor Vitae ; Nguyen Van Duy^a ; ¹ ; ^{nguyenvanduy@itims.edu.vn" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Nguyen Thi Phuong^aAuthor Vitae ; Nguyen Ngoc Trung^bAuthor Vitae ; Chu Manh Hung^aAuthor Vitae ; Nguyen Duc Hoa^aAuthor Vitae ; Nguyen Van Hieu^a ; ¹ ; ^{hieu@itims.edu.vn" class="auth_mail" title="E-mail the corresponding author}Author Vitae
• 关键词：CNTs/SnO2 NWs ; n-p-n heterojunction ; Gas sensors ; ppb level NO2
• 刊名：Sensors & Actuators: B. Chemical
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：238
• 期：Complete
• 页码：1120-1127
• 全文大小：2049 K

文摘

The enhancement of sensor performances for the detection of highly toxic NO₂ gas is one of the most important technological issues in the realization of devices for environmental pollution monitoring. Herein, the n-p-n heterojunctions of carbon nanotubes (CNTs) and SnO₂ nanowires (NWs) are designed and fabricated by a facile method to investigate their NO₂ gas-sensing performance. The designed devices are easily realized by first growing the SnO₂ NWs on Pt electrodes using a thermal chemical vapour deposition method and then spray coating the single-walled carbon nanotubes (SWCNTs) and/or multi-walled carbon nanotubes (MWCNTs) to make a connection between the two electrodes. The MWCNTs/SnO₂ NWs device has much higher NO₂ responsiveness compared to the SWCNTs/SnO₂ NWs and the pristine SnO₂ NWs devices. The fabricated devices showed ultrahigh enhancement in gas sensing performance for NO₂, whereas these characteristics do not significantly improve for H₂S gas. At a low working temperature of 100 °C, the fabricated sensors are able to detect the NO₂ gas concentration down to 20 ppb. We also clarify the sensing mechanism of the fabricated devices.