These structure and composition of the P3GC film are appropriate for making film sensors, whose resistance changes as a function of gas concentration. Monitoring ammonia gas by the sensors showed that the responding time of the sensing reached a value as fast as 30 s, the response at ammonia gas content of 10 ppm attained a value as large as and the relative sensitivity was of %/ppm. | Communications in Physics, Vol. 28, No. 4 (2018), pp. 369-377 DOI: CHARACTERIZATION OF NH3 SENSING PROPERTIES OF P3HT+RGO+CNT COMPOSITE FILMS MADE BY SPIN-COATING LAM MINH LONG1 , NGUYEN NANG DINH1,† , AND TRAN QUANG TRUNG2 1 University of Engineering and Technology, VNU in Hanoi, No. 144 Xuan Thuy Road, Cau Giay District, Hanoi, Vietnam 2 University of Natural Science, VNU in Ho Chi Minh City, 227 Nguyen Van Cu Road, District 5, Ho Chi Minh City, Vietnam † E-mail: dinhnn@ Received 26 June 2018 Accepted for publication 19 October 2018 Published 15 December 2018 Abstract. Thin films of poly(3-hexylthiophene) (P3HT) incorporated with reduced graphene oxide (rGO) and multi-walled carbon nanotubes (CNTs) were prepared by spin-coating technique. Atomic force microscope (AFM) surface morphology, UV-Vis spectra and NH3 gas sensing of the films were studied. Results showed that the P3HT embedded with a content of 20 wt.% of rGO and 10 % of CNTs (abbreviated to P3GC) resulted in the formation of nanostructured composites, exhibiting nm-roughness surface and a semiconducting material with a bandgap of . These structure and composition of the P3GC film are appropriate for making film sensors, whose resistance changes as a function of gas concentration. Monitoring ammonia gas by the sensors showed that the responding time of the sensing reached a value as fast as 30 s, the response at ammonia gas content of 10 ppm attained a value as large as and the relative sensitivity was of %/ppm. Keywords: P3HT+rGO+CNT composite; surface morphology; UV-Vis spectra; NH3 gas sensors; sensing response. Classification numbers: ; ; ; . c 2018 Vietnam Academy of Science and Technology 370 CHARACTERIZATION OF NH3 SENSING PROPERTIES OF P3HT+RGO+CNT COMPOSITE FILMS . I. INTRODUCTION Ammonia is a compound of nitrogen and hydrogen with the formula NH3 . It contributes significantly to the .
