Han Shijiao, Yang Zuchong, Li Zongkang, Zhuang Xinming, Akinwande Deji, Yu Junsheng
State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering , University of Electronic Science and Technology of China (UESTC) , Chengdu 610054 , P. R. China.
Microelectronics Research Center , The University of Texas at Austin , Austin , 78758 Texas , United States.
ACS Appl Mater Interfaces. 2018 Nov 7;10(44):38280-38286. doi: 10.1021/acsami.8b07838. Epub 2018 Oct 26.
Over the past decades, organic field-effect transistor (OFET) gas sensors have maintained a rapid development. However, the majority of OFET gas sensors show insufficient detection capability towards oxidizing gases such as nitrogen oxide, compared with the inorganic counterpart. In this paper, a new strategy of OFET nitrogen dioxide (NO) gas sensor, consisting of poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly(9-vinylcarbazole) (PVK) blend, is reported. Depending on the gate voltage, this sensor can operate in two modes at room temperature. Of the two modes exposed to NO for 5 min, when the gate voltage is 0 V, the highest NO responsivity of this OFET is >20 000% for 30 ppm (≈700% for 600 ppb) with the 1:1 P3HT/PVK blend, it is ≈40 times greater than that with the pure P3HT. The limit of detection of ≈300 ppb is achieved, and there is still room for improvement. While in the condition of -40 V, the response increases by 15 times than that with the pure P3HT. This is the first attempt to improve the OFET sensing performance using PVK, which usually functions as a hole-transport layer in the light- emitting device. The enhancement of sensing performance is attributed to the aggregation-controlling and hole-transporting/electron-blocking effect of PVK. This work demonstrates that the hole-transport material can be applied to improve the NO sensor with simple solution process, which expands the material choice of OFET gas sensors.
在过去几十年中，有机场效应晶体管（OFET）气体传感器一直保持快速发展。然而，与无机气体传感器相比，大多数OFET气体传感器对氮氧化物等氧化性气体的检测能力不足。本文报道了一种由聚（3-己基噻吩-2,5-二亚基）（P3HT）和聚（9-乙烯基咔唑）（PVK）共混物组成的新型OFET二氧化氮（NO）气体传感器策略。根据栅极电压，该传感器可在室温下以两种模式工作。在两种模式下暴露于NO 5分钟，当栅极电压为0 V时，对于30 ppm（600 ppb时约为700%）的1:1 P3HT/PVK共混物，该OFET的最高NO响应率>20000%，比纯P3HT高约40倍。实现了约300 ppb的检测限，仍有改进空间。而在-40 V的条件下，响应比纯P3HT增加了15倍。这是首次尝试使用通常在发光器件中用作空穴传输层的PVK来提高OFET传感性能。传感性能的增强归因于PVK的聚集控制和空穴传输/电子阻挡效应。这项工作表明，空穴传输材料可通过简单的溶液工艺应用于改进NO传感器，这扩展了OFET气体传感器的材料选择范围。
