Synthesis And Properties Of Solution-processed P-n Conjugated Molecules With Star-shaped Architectures For Narrow Bandgap Modulation

In this thesis, three series of star-shaped p-n conjugated molecules have beed designed,synthesized, and characterized. The thermodynamic properties, spectroscopic properties,electrochemical experiments as well as the resulting optoelectronic properties have beeninvestigated. The molecular structure of the three series of materials and the relationshipbetween the photoelectric properties have been studied. Main results are as follows:1. Two new star-shaped molecules with phenylcarbazole(CBZ) as core, thiophene-benzothiadiazole derivatives as arm, S1and S2, Intramolecular charge transfers wereobserved in both molecules from their absorption spectra. S2absorption edge expandedto690nm, and S1showed a broad absorption band from350nm to650nm. The deviceswere fabricated using PCBM as an acceptor. The power conversion efficiency (PCE) ofsolar cell were0.34%and0.5%using S1and S2as donor respectively.2. Two new star-shaped molecules with triphenylamine(TPA) as core, thiophene-benzothiadiazole derivatives as arm, S3and S4. S4based on pyrene, naphthalene,fluorophenyl, cyano benzene obtained as an end group of four new compounds T1, T2,T3and T4. Spectroscopy and cyclic voltammetry method were used to study a change inend groups on the molecular absorption wavelength and optical luminescence coloreffects and the regulating role on the molecular level. These compounds are potential redmaterial specific luminescent properties to be further made devices.3. Design and synthesis and carbazole (TAT) for the nuclear, pyrene (Py) capped three starcompounds M1, M2, M3. By adjusting the proportion to the receptor unit and theposition in the molecular skeleton, the research to a number of receptor structure, location,type of molecular structure on the performance of the materials.