Conjugated polymers have attracted much interest in the last several years for their versatilities and potential application in light-emitting devices. Hyperbranced polymers have been intensively investigated recently due to their good solubility

processability

tunable physical and chemical properties and easy synthesis by called one-pot reaction. Our aim was to synthesize hyperbranched conjugated polymers combining the merits of both dendrimer-like structure and linear conjugated units. In order to improve hole-transporting ability of the material

triphenylamine was introduced into the polymer as connecting units. With triphenylbenzene as cores

a novel hyperbranched polymer (TPA-TPP) was synthesized based on A

2

+B

3

reaction. The synthetic method

molecular structure and photophysical properties were investigated systematically. TPA-TPP showed good solubility

film-performing property and high thermal stability. The polymer was synthesized with molecular weight of 1 700; the relative low value was related to the Wittig-reaction used in the synthesis and the large steric hindrance of the branches. Due to the electron-donating triphenylamine moieties

it would be expected that the twisted intramolecular charge transfer state (TICT) exist at the excited state

which was evidenced by the solvent effect of polymer fluorescent spectra. TPA-TPP showed a broad and structureless emission band

and the peak position of the band red shifted with the increase of solvent polarity

the way of tuning emission wavelength of the material by simply changing the environment of TPA-TPP distributed may be provided. Fluorescent spectra of TPA-TPP showed that there was a red-shift of 10nm only from dichloromethane solution to thin film

which was much smaller than those of the linear conjugated polymers (normally larger than 50nm). The reason may be due to the large steric hindrance caused by triphenylbenzene and triphenylamine. Our results exhibited that by introducing groups with large steric hindrance into the light-emitting polymer

the red-shift of emission band from solution to film could be reduced

which was favorable for application in light-emitting devices. Light-emitting diodes with the structure ITO/PEDOT/TPA-TPP/Ba/Al have been fabricated. The electroluminescence spectrum of TPA-TPP exhibits a broader profile with emission ranging from 430nm to 740nm.