Design, Synthesis And Optoelectronic Properties Of Polyindoles And Their Derivatives

In recent years, organic semiconductor materials with low production cost, species andstructural diversity, performance can be modulated by structural design, preparation of synthesisprocess is simple, easily to be prepared and can be used for large-area flexible electronic devices,etc. have attracted widespread attention. Type of organic molecules by tailoring the design andstructure of the materials developed from the organic semiconductor material storage constraints,the nature of the regulation of the material to improve the performance of the device in order toobtain a large number of materials with intended function.This paper introduces the basic principles of organic electroluminescence, and the status quo ofthe development of small organic molecules indole solar cell material trimer a simple exposition.Meanwhile designed and synthesized a series of material soluble trimeric indole small organicmolecules narrowband lines and tetramer-based multi-substituted indole derivatives, and their light,thermal stability and electrochemical properties were studied based on the discussion. Details are asfollows:(1) Synthesis of a series of three carbazole-terminated poly-symmetrically substitutedbenzothiadiazole derivatives small molecule-based material through a narrowband Suzuki couplingmethod. Studies have shown that: These small molecules have a good solubility, a broad absorptionspectrum and a high thermal stability. Thermal gravimetric analysis (TGA) study shows that thesesmall molecular materials have better thermal stability. And is conducive to the solution ofamorphous processing. UV-visible absorption spectroscopy studies have found that by adjusting theposition of the conjugate molecules and the alkyl chain length, effectively broadening theabsorption spectrum of the molecules, reducing the bandgap conjugated molecules.Electrochemical measurements and theoretical calculations are consistent. Adjusting the band gapof linear molecules from1.99to1.75eV. Suggest that three carbazole and the possibility ofconstructing narrow-band materials.(2) To further broaden the absorption spectrum of the compound to the strong electron-donatinggroup and triindole or triazatruxene (TAT), diketopyrrolopyrrole, benzothiadiazole, and theintroduction of thiophene and benzo-thiadiazole-based electron-withdrawing groups, solubilityobtained a good linear series of small organic molecules. Thermal gravimetric analysis (TGA) studyshows that these small molecular materials have better thermal stability. And is conducive to the solution of amorphous processing. The electrochemical test by UV absorption and that: the series ofcompounds having a broad absorption spectrum and a low bandgap. Among DPP nuclear materialhas a wider spectral absorption, the introduction of thiophene benzothiazole group, more conduciveto visible light absorbing compounds. The electrochemical test results can be seen from the lowerlevel of this series LUMO small molecule materials conducive electron injection and transport. Theelectrochemical test results show,2BDT narrower (TATBT)2DPP bandgap ratio (TATBT)BDT, theresults of which are consistent with the theoretical calculations.(3) In large flat with good thermal and chemical stability of perylene nucleus, indole trimer(three and carbazole) was capped, and another group of narrow-band system of linear syntheticsmall molecules, thienyl and thiazolyl introduced group received two very good dissolution of smallorganic molecules. The electrochemical test by UV absorption and that: the series of compoundshaving a broad absorption spectrum and a very low bandgap. A thienyl group is introduced, thecompound LUMO lower HOMO value increases. Reduce overall energy gap, this result isconsistent with the theoretical calculations. Will be more strong electron-withdrawing ability of PDIunit fully to the energy gap of three and carbazole series materials by the beginning of1.99eV to1.36eV.(4) Obtained by cyclization of a new building blocks-indole tetramer. And a fluorenyl groupand pyrenyl synthesized capped four and eight-substituted substituted derivatives thereof. Thisseries of multi-arm structure of macromolecules having a narrow absorption and emission spectra.Electrochemical studies show that when the number of the substituent introduced increases, HOMOenergy level of the compound is increased, while reducing LUMO level, i.e., the band gap isnarrowed. Fluorene substituted pyrene derivatives substituted derivative than the band gap of wideband gap. The results agree with the theoretical calculations.