화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals, Vol.498, 183-192, 2009
Raman Spectra and Current-Voltage Characteristics of 4,4',4''-Tris(2-naphthylphenylamino)triphenylamine Thin Films
A thin film of vacuum- deposited 2-TNATA (4,4',4 ''-Tris(2-naphthylphenylamino) triphenylamine), usually used as a hole injection layer (HIL) in OLEDs, was annealed after deposition and treated with electromagnetic field in order to get the film molecularly-ordered and analyzed by AFM, SEM and Raman spectroscopy. The treated film was placed between indium tin oxide (ITO) electrode and hole injection layer to investigate the current density-Voltage (J-V) and luminance-voltage (L-V) characteristics of the organic light-emitting diodes. According to the Raman spectra results, as-deposited 2-TNATA thin film was not molecularly ordered, and the films treated by the thermal annealing at near the glass transition temperature of 2-TNATA and electromagnetic field, were molecularly ordered and showed the significant increases of current density and luminance efficiency for devices at a given voltage compared to an as-deposited 2-TNATA film.