Synthesis and properties of phenothiazylene vinylene‐based polymers: New organic semiconductors for field‐effect transistors and solar cells

Abstract

A series of new phenothiazylene vinylene‐based semiconducting polymers, poly[3,7‐(4′‐dodecyloxyphenyl)phenothiazylene vinylene] (P1), poly[3,7‐(4′‐dodecyloxyphenyl)phenothiazylene vinylene‐alt‐1,4‐phenylene vinylene] (P2), and poly[3,7‐(4′‐dodecyloxyphenyl)phenothiazylene vinylene‐alt‐2,5‐thienylene vinylene] (P3), have been synthesized via a Horner‐Emmons reaction. FTIR and 1H NMR spectroscopies confirmed that the configurations of the vinylene groups in the polymers were all‐trans (E). The weight‐averaged molecular weights (Mw) of P1, P2, and P3 were found to be 27,000, 22,000, and 29,000, with polydispersity indices of 1.91, 2.05, and 2.25, respectively. The thermograms for P1, P2, and P3 each contained only a broad glass transition, at 129, 167, and 155 °C, respectively, without the observation of melting features. UV–visible absorption spectra of the polymers showed two strong absorption bands in the ranges 315–370 nm and 450–500 nm, which arose from absorptions of the phenothiazine segments and the conjugated main chains. Solution‐processed field‐effect transistors fabricated from these polymers showed p‐type organic thin‐film transistor characteristics. The field‐effect mobilities of P1, P2, and P3 were measured to be 1.0 × 10−4, 3.6 × 10−5, and 1.0 × 10−3 cm2 V−1 s−1, respectively, and the on/off ratios were in the order of 102 for P1 and P2, and 103 for P3. Atomic force microscopy and X‐ray diffraction analysis of thin films of the polymers show that they have amorphous structures. A photovoltaic device in which a P3/PC71BM (1/5) blend film was used as the active layer exhibited an open‐circuit voltage (VOC) of 0.42 V, a short circuit current (JSC) of 5.17 mA cm−2, a fill factor of 0.35, and a power conversion efficiency of 0.76% under AM 1.5 G (100 mW cm−2) illumination. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 635–646, 2010

Synthesis and characterization of thermally stable polyimides with a pendent phenothiazine unit based on new diamine 10-(3,5-diaminobenzoyl)phenothiazine

“…Polymers and organic molecules containing phenothiazine or their derivatives have attracted considerable interest on the account of their unique electro-optical properties, which makes these molecules potential candidates for diverse applications in photoluminescence, chemiluminescence, 16 and energy as well as data storage devices. Recently, phenothiazine polymers have been used in polymer lightemitting diodes, [16][17][18][19] organic field-effect transistors, [20][21] and organic solar cells. 22,23 In this study, incorporation of a bulky substituent like tricyclic phenothiazine unit into rigid PI backbone was carried out.…”

White Light Emitting Polymers from a Luminogen with Local Polarity Induced Enhanced Emission

“…FCPA did not show any peak in XRD, suggesting that FCPA is completely amorphous (Figure 6). 51 The differential scanning calorimetry (DSC) of FCPA (Figure S13, Supporting Information) revealed that the melting point of FCPA was 48.7 °C and the absence of the crystallization peak on the cooling cycle indicated that the compound is amorphous and explained its film-forming property. This observation is in contrast to the previous AIE molecules reported with phenothiazine and bulky aromatic groups.…”

Synthesis, characterization, photophysical properties, and computational studies on N-hexylphenothiazine/cyanopyridine based π-conjugated copolymers

“…They are also characterized by high electrical and thermal stability, with high excellent electro-optical characteristics in devices. [51][52][53] Phenothiazine was used as electron donor, with benzothiadiazole, possessing a robust electron affinity as electron acceptor, and thiophene with rich electrons linked to each end to increase p-conjugation efficiency. This provides a design of a basic molecular structure, affording a low band gap polymer.…”