Structure optimization of organic light-emitting devices

Abstract

A triple layer organic light-emitting diode (OLED) with two heterostructure of indium-tin oxide (ITO)/N,N′-diphenyl-N, N′-bis(1-naphthyl) (1,1′-biphenyl)-4,4′-diamine (NPB)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/ 8-Hydroxyquinoline aluminum (Alq₃)/Mg:Ag has been fabricated by using the vacuum deposition method. The influence of different film thickness of BCP layer on the performance of the OLEDs has been investigated. The results show that when the thickness of the BCP layer film gradually ranges from 0.1-4.0 nm, the electroluminescence (EL) spectra of the OLEDs shift from green to greenish-blue to blue, and the BCP layer acts as the role for the recombination region of charge carriers related to EL spectrum, which enhances the brightness and power efficiency. The power efficiency of the OLEDs reaches to as high as 7.3 lm/W.

Keywords

Power Efficiency / Forward Bias / Emissive Layer / Recombination Region / Heterostructure Device

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