Polyethers containing 3,6-diarylcarbazolyl groups as polymeric materials for hole transporting layers of OLEDs

Abstract

Several polyethers containing pendent 3,6-diarylcarbazolyl moieties have been synthesized by the multi-step synthetic routes. Full characterization of their structures is presented. The polymers represent materials of high thermal stability with initial thermal degradation temperatures exceeding 419°C. The glass transition temperatures of the amorphous materials were in the range of 66-108°C. The electron photoemission spectra of thin layers of the polymers showed ionization potentials in the range of 5.47-5.69 eV. Hole transporting properties of the polymeric materials were tested in the structures of organic light emitting diodes with Alq 3 as the green emitter. The device containing hole transporting layers of the polymer with 3,6-di(4-biphenyl)carbazolyl moieties exhibited the best overall performance with a maximum photometric efficiency of about 2.3 cd/A and maximum brightness exceeding 2630 cd/m 2 .

Incorporating a hole-transport material into the emissive layer of solid-state light-emitting electrochemical cells to improve device performance

“…31 Complex 1 was purchased from Luminescence Technology. 32 Indium tin oxide (ITO)-coated glass substrates were cleaned and treated with UV/ozone prior to use. 1).…”

“…Synthesis procedures of PPCO are reported elsewhere. 32 Indium tin oxide (ITO)-coated glass substrates were cleaned and treated with UV/ozone prior to use. A thin poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) layer (30 nm) was spin-coated at 4000 rpm onto the ITO substrate in air and was then baked at 150 1C for 30 min.…”