Three-dimensional CuPc films decorated with well-ordered PVA parallel nanofiber arrays for low concentration detecting NO2 sensor

Well-ordered polyvinyl alcohol (PVA) parallel nanofiber arrays (PNAs) were fabricated by using electrospinning receiving board with clined gap. A three-dimensional (3D) copper phthalocyanine (CuPc) organic field effect transistor (OFET) sensor was obtained by evaporating CuPc on the PVA PNAs. This 3D structure is conducive to the multi angle adsorption and desorption of the target gas and active layers. The detection limit of the obtained sensors is lower, and the response and recovery time are also shorter. Compared with single CuPc films and CuPc films with disordered PVA nanofibers sensors, the minimum detection concentration is reduced by one third. The CuPc/PVA PNAs sensors have been successfully used in real-time monitoring of NO2 at 0.3 ppm. The response and recovery time of the CuPc/PVA PNAs sensors are both 0.02 min for 25 ppm NO2. The response and recovery time are 350 and 130 times faster than those of CuPc sensors with disordered PVA nanofibers, respectively. Humidity has little effect on the response of the sensor. This convenient and effective method to prepare high performance OFET sensors can be extended to other gas monitoring.

Automated summary

The CuPc/PVA PNAs sensors, with well-ordered nanofiber arrays, achieved lower detection limit and shorter response and recovery time for gas monitoring compared to sensors with disordered nanofibers. The sensors showed promising results in real-time monitoring of NO2, with minimal impact from humidity.