Organic light emitting diodes (OLEDs) with the structure of indium-tin-oxide glass/spin-coated poly[2-(N-carbazolyl)-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene]/8-hydroxyquinoline aluminum/Li:Al [ITO-glass/CzEH-PPV/Alq3/Li:Al] have been fabricated by applying three deposition methods: physical vapor deposition (PVD), neutral and ionized cluster beam depositions (NCBD and ICBD). Atomic force microscopy (AFM) measurements show that the weakly bound and highly directional cluster beam is effective in producing uniform flat film surfaces. Photo- and electro-luminescence (PL, EL) spectra demonstrate that the NCBD and PVD methods produce more efficient EL devices and the introduction of neutral buffer layer to the ICBD devices enhances the performances. DCM-doped devices show color-tuning capability and higher external quantum efficiency (EQE) compared to undoped devices.
- Atomic force microscopy
- Optical spectroscopy
- Poly(phenylene vinylene) derivative
- Vapor and cluster depositions