Improved performances in light-emitting diodes based on a semiconductor TiO2 nano cluster buffer layer

Phuong Hoai Nam Nguyen and Nang Dinh Nguyen

Abstract

Ultra-thin films of TiO₂ nano clusters were fabricated and characterized by field- emission scanning electron microscopy (FE-SEM) and transmittance measurements. The x-ray spectra of the TiO₂ nano crystals were also studied. The performances of the devices based on the blended conducting polymer are improved by inserting a semiconducting layer of TiO₂ nano cluster into the emissive poly[9-vinylcarbarzole] (PVK)/ poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and Al cathode. The organic light-emitting diodes (OLEDs) show high efficiency and good stability with turn-on voltage lower than 3 V and current density higher than 0.5 mA mm⁻²