Abstract This paper investigates the electrical, morphological, and mechanical behavior of ultrathin layer-by-layer polyaniline/poly(vinyl sulfonic acid) (PANI/PVS) ultrathin films for ammonia gas sensing. Atomic force microscopy shows that the PANI/PVS surface's roughness increases almost linearly with the number of PANI/PVS bilayers, while the surface morphology varies from a rod-like structure to a film-like architecture. Impedance measurements and their representation by a Cole-Cole model confirm this transition at ~15 bilayers. The designed sensor shows low response time (< 1 min), an optimal operating frequency range (1–100 Hz), high stability and sensibility to ammonia (~ 98 kΩ/ppm), and low sensibility to strain (~ 3.6 kΩ/%). This study suggests that hopping carriers' concentration remains constant, and hopping carriers' mobility changes with the number of bilayers. The simultaneous analysis of morphology with complex impedance measurements is a strategy for enhancing the electrical performance of low-cost and flexible organic sensing devices. morphological layerbylayer layer polyaniline/polyvinyl polyanilinepolyvinyl polyaniline/poly vinyl polyaniline poly acid PANIPVS PANI PVS (PANI/PVS surfaces s bilayers rodlike rod like filmlike film architecture ColeCole Cole 15 ~1 < ( min, min , min) 1–100 1100 100 (1–10 Hz, Hz Hz) ~ 9 kΩ/ppm, kΩppm kΩ/ppm kΩ ppm kΩ/ppm) 36 3 6 3. kΩ/%. kΩ/% . kΩ/%) carriers constant lowcost cost devices polyvinyl polyanilinepoly 1–10 110 10 (1–1 kΩ/ 1–1 11 (1– 1– (1

Abstract This paper investigates the properties of the polyaniline (PANI) on açaí vegetable fiber (AVF), hereafter referred to as PANI-COATED:AVF. Scanning electron and atomic force microscopy showed that the incorporation of PANI produced a linear surface, while optical microscopy images showed that the semiconductor layer was flawed. The complex impedance measurements performed at room temperature indicated that the electrical properties of PANI were fully transferred to the PANI-COATED:AVF and that the Cole-Cole approach dominated over a frequency range from 1 Hz to 100 kHz. Thermogravimetric analysis revealed a thermal stability range of 0° to 300°C. Finally, the combination of PANI with AVF was a successful due to the ease of processing and obtaining semiconductor filaments with wide ranges of thermal and electrical stability. This article is a complement to another recently published [doi.org/10.1002/pc.27068]. (PANI AVF, , (AVF) PANICOATEDAVF. PANICOATEDAVF COATED AVF. surface flawed ColeCole Cole 10 kHz 0 300C C 300 300°C Finally doi.org/10.1002/pc.27068. doiorg101002pc27068 doiorgpc doi.org/10.1002/pc.27068 . doi org 1002 pc 27068 [doi.org/10.1002/pc.27068] (AVF 30 doiorg doiorg101002pc2706 doi.org/10.1002/pc.2706 2706 [doi.org/10.1002/pc.27068 3 doiorg101002pc270 doi.org/10.1002/pc.270 270 [doi.org/10.1002/pc.2706 doiorg101002pc27 doi.org/10.1002/pc.27 27 [doi.org/10.1002/pc.270 doiorg101002pc2 doi.org/10.1002/pc.2 2 [doi.org/10.1002/pc.27 doiorg101002pc doi.org/10.1002/pc. [doi.org/10.1002/pc.2 doi.org/10.1002/pc [doi.org/10.1002/pc. [doi.org/10.1002/pc

In this work we investigated the effect of visible radiation on the electrical properties of poly[(2-methoxy-5-hexyloxy)-p-phenylenevinylene]- MH-PPV films and light emitting diodes. Complex impedance measurements of (Au or ITO)/MH-PPV/(Au or Al) samples were carried out at room temperature and exposed to white light. Over the frequency range from 100 mHz to 2 MHz, the electrical results of Au/MH-PPV/Au was dominated by the Cole-Cole approach, where the electrode influence is negligible. However, some additional influence of the interface was observed to occur when Al was used as electrode. These effects were observed under both dark and visible-light illumination conditions. A simple model based on resistor-capacitor parallel circuits was developed to represent the complex impedance of the samples, thereby separating bulk and interface contributions. We observed that the polymer electrical resistivity decreased while the dielectric constant of the polymer and the thickness of the Al/MH-PPV layer were almost constant with increasing light intensity. The decrease of the polymer layer resistance comes from a better charge injection due to a light induced dissociation of positive charge carriers at the electrode.