Synthesis And Electrochromic Properties Of Conjugated Polymers Based On Dioxythiophene And Quinoxaline Derivatives

Conductive polymers break the perception that organic material cannot be electrically conductive.In the decades since its inception,many experts and scholars have synthesized and studied countless conductive polymers.Conductive polymers also exhibit rich colors,easy-to-adjust band gaps,excellent optoelectronic properties,and processability,and are widely used in organic electrochemical transistors(OECTs),organic field effect transistors(OFETs),and thermoelectric(TE) materials,organic solar energy(OSCs)materials,organic photovoltaics(OPVs) and other fields.In this paper,we first synthesize two pre-monomers of dioxythiophene derivative and tetrachloroquinoxaline,and then synthesize four series of eleven conductive polymers by chemical polymerization according to D-A theory.These four series of polymers contain four colors of yellow,cyan,red and green,respectively.(1)In the second chapter,we use dioxythiophene derivatives as electron donors,benzothiadiazole derivatives as electron acceptors,and benzene rings to adjust optical forbidden bands.Three kinds of electrochromic polymers(PBBT1,PBBT2,PBBT3) which changed from neutral yellows and oxidized grays were synthesized and characterized.They all have good optical contrast and stability in both the visible and near-infrared regions,and also with high coloring efficiency.The optical contrast of PBBT1 in the near-infrared region is over 75%,and the optical contrast of PBBT3 in the visible region is over 40%,both of them have good application prospects.(2)In the third chapter,we use dioxythiophene derivatives as electron donors,pyrrolopyrroledione derivatives as electron acceptors,selenophene to adjust optical band gaps,and three kinds of electrochromic polymers(PSPT1,PSPT2,PSPT3) that change between neutral cyan and oxidation blues were synthesized,their UV absorption peaks appear in the near-infrared region(800nm-2000nm),and have a very low optical band gap(1.22 eV,1.17 eV,1.21 eV respectively),can be classify as a low bandgap polymer(<1.5eV),all of them can be used in the near infrared field.(3)In the fourth chapter,we use benzodithiophene derivatives and dithienocyclodecadiene derivatives as electron donors and tetrachloroquinoxaline as electron acceptors,synthesized two kinds of neutral red and oxidized greens electrochromic polymer(PBPP1,PBPP2).All two polymers have lower initial oxidation voltages(0.9V and 0.86 V,respectively)and optical band gaps,and they has a faster response time in the process of doping in the visible region(<1.5s) and dedoping in the near-infrared region(less than 0.5s).(4)In the fifth chapter,we used thieno[3,2-b] thiophene and carbazole derivatives as electron donor units and pyrrolopyrroledione derivatives as electron accepting units to synthesize three electrochromic polymers(PTPC1,PTPC2,PTPC3),which changed from neutral green states to oxidized gray-black.The three polymers have an ultraviolet absorption peak at 430 nm and 700 nm in the visible region,and the wavelength energy at 700 nm in sunlight incident on the ground is the strongest,therefore all three polymers have the potential of solar cell materials.