From aerospace to screen: Multifunctional poly(benzoxazine)s based on different triarylamines for electrochromic, explosive detection and resistance memory devices

Four kinds of main-chain benzoxazine polymers (PBZ) containing triarylamine (TAA) units were synthesized by Mannich reaction and characterized by ¹H nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) techniques, etc. Thermal, optical, photophysical and electrochemical properties were studied. The 50% of char residue is left in N₂ at 800 °C. The polymers are soluble in common organic solvents and easily spin-coated onto indium‑tin oxide (ITO) coated glass substrates. All the polymers have voltage window ranging from 0 to 1.8 V, and the colors change from yellowish to dark red when voltage is applied. Meanwhile, device assembled from polymer exhibit significant color changes. Furthermore, the polymers also have promising potential application in explosive detection and resistance memory devices.

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic-organic hybrid perovskite solar cells

The ever increasing demand for clean energy has encouraged researchers to intensively investigate environmentally friendly photovoltaic devices. Inorganic-organic hybrid perovskite solar cells (PSCs) are very promising due to their potentials of easy fabrication processes and high power conversion efficiencies (PCEs). Designing hole-transporting materials (HTMs) is one of the key factors in achieving the high PCEs of PSCs. We now report the synthesis of two types of carbazole-based polymers, namely 3,6-Cbz-EDOT and 2,7-Cbz-EDOT, by Stille polycondensation. Despite the same chemical composition, 3,6-Cbz-EDOT and 2,7-Cbz-EDOT displayed different optical and electrochemical properties due to the different connectivity mode of the carbazole unit. Therefore, their performances as hole-transporting polymeric materials in the PSCs were also different. The device based on 2,7-Cbz-EDOT showed better photovoltaic properties with the PCE of 4.47% than that based on 3,6-Cbz-EDOT. This could be due to its more suitable highest occupied molecular orbital (HOMO) level and higher hole mobility.

Ultrahigh electron-deficient pyrrolo-acenaphtho-pyridazine-dione based donor–acceptor conjugated polymers for electrochromic applications

New ultrahigh electron-deficient acceptors pyrrolo-acenaphtho-pyridazine-diones (PAPD) were synthesized via a regio-selective inverse electron demand Diels–Alder reaction and their corresponding conjugated polymers showed electrochromism with long-term stability.