Nanoparticle-induced resonant tunneling behaviors in small molecule organic light-emitting devices

Abstract

We report a hybrid nanoparticle/organic device with strong resonant tunneling behavior by introducing ligand-capped Ag nanoparticles between indium tin oxide and hole transport layer in small molecule organic light-emitting devices. The dependences of resonant tunneling current on the thickness of the organic layers are investigated. For the optimized device, a peak-to-valley current ratio as high as 4.5 and narrow peak width about 1.8 V are obtained. Combining with the analysis of current-voltage behavior, the mechanism based on the charge trapping effect of Ag nanoparticles is proposed to interpret the operation of the hybrid device. Finally, the emission characteristics of hybrid devices are also studied.