Synthesis and Characterization of Regioregular Poly(3-hexylthiophene) applied in a Dual Electrochromic Device

Abstract

The polyaniline (PANI) and regioregular poly(3-hexylthiophene) (P3HTr) are polymers synthesized easily, can be deposited as a film by various techniques, are materials that exhibit a variety of colors to go through oxidation processes and reduction by applying an external potential, both polymers have an immediate response rate of color. The electrochemical behavior of the PANI and P3HTr is complementary, that is, if a positive potential to the device is applied, the PANI film is oxidized while the P3HTr film is reduced, on the other hand, if a negative potential is applied, the PANI film is reduced while the P3HTr film is oxidized. Both films in its redox process are clarified and obscured at the same time, this color change provides a significant difference in optical transmittance on a dual electrochromic device (DED's).In this research, regioregular poly(3-hexylthiophene) was synthesized and characterized, films were deposited by spin-coating and dip-coating techniques. Polyaniline films were deposited by chemical bath and spin-coating techniques. Dual electrochromic devices based on P3HTr and PANI were prepared. The devices were studied by UV-vis spectroscopy at three different voltages: 1.4 V, 0 V and -1.4 V, optical kinetic tests were also performed at 550 nm applying a positive potential (1.4 V) and negative (-1.4 V). The results indicated the wavelength where both (PANI and P3HT) reach the greatest difference in transmittance. The influence of deposit type of polymer films on electrochromic response was determined.