A subparts per million-sensitive nitrogen dioxide (NO2) sensing circuit with improved humid air stability was realized incorporating UV-ozone treatment on a poly(bisdodecylquaterthiophene)/polystyrene blend film. The circuit consisted of a pair of organic field-effect transistors (OFETs) in series, one OFET with and one without this treatment. In contrast to most previous OFET sensors, the readout was obtained from the voltage Vout at a point between the OFETs. The circuit showed a low detection limit (200 ppb) toward NO2 and greatly reduced the voltage drift in the humid environment compared to the current drift of the circuit or the individual OFETs because of the balance of conductance drifts on either side of the readout point, which differs from the existing OFET-based sensors. By using Vout as the detection parameter, the sensitivity of the circuit approaches 25 and 400% for NO2 concentrations of 200 ppb and 20 ppm, respectively. Moreover, the Vout is substantial enough to be easily measured by a voltmeter, which could remove the need for complex equipment (semiconductor analyzer system) for the sensing test. We thus demonstrate a simplified approach to stabilized OFET circuits that could be used in printable, flexible, or wearable sensors.

中文翻译：

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基于聚合物半导体氧化的具有改善的信噪比的湿空气可操作，NO2响应的聚合物晶体管串联电路。

在聚（双十二烷基四噻吩）/聚苯乙烯共混膜上结合了紫外线臭氧处理，实现了具有百万分之几敏敏的二氧化氮（NO2）敏感电路，具有改善的湿空气稳定性。该电路由一对串联的有机场效应晶体管（OFET）组成，其中一个带有OFET，一个没有经过这种处理。与大多数以前的OFET传感器相反，该读数是从OFET之间的点处的电压Vout获得的。与电路或单个OFET的电流漂移相比，该电路对NO2的检测限低（200 ppb），并且由于在读数点两侧的电导漂移的平衡，大大降低了潮湿环境中的电压漂移，与现有的基于OFET的传感器不同。通过使用Vout作为检测参数，对于200 ppb和20 ppm的NO2浓度，电路的灵敏度分别接近25％和400％。此外，Vout足够坚固，可以通过电压表轻松测量，这可以消除对用于传感测试的复杂设备（半导体分析仪系统）的需求。因此，我们展示了一种稳定的OFET电路的简化方法，该方法可用于可打印，柔性或可穿戴式传感器中。