Localized surface plasmon resonance effect in organic light-emitting devices with Ag islands

Abstract

We report on luminescence enhancement of organic light-emitting devices (OLEDs) with silver islands (i-Ag) by a localized surface plasmon resonance (LSPR) effect. The devices were fabricated using tetraphenylporphyrin (TPP) as the red emission material, bis[N-(1-naphthyl)-N-phenyl] benzidine (α-NPD) as the blue emission and hole transport material, and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) as the electron transport material. To clarify the position of emission enhancement by energy transfer from i-Ag, an ultrathin TPP layer located within the α-NPD layer. In the device with i-Ag and the TPP layer located over 10 nm from i-Ag, TPP emission was enhanced in comparison with the device without i-Ag. The enhancement of TPP emission was suggested to be the effect of the enhanced electric field resulting from LSPR excited by α-NPD emission.

MoO3/Ag/MoO3anode for organic light-emitting diodes and its carrier injection property

“…Deposited films of Ag are composed of tiny islands in the initial process of growth. 32,33) In general, Ag nanoparticles or Ag islands easily cause a local surface plasmon resonance (LSPR) effect with characteristic absorption of light in the visible range, and the continuous film limits an excitation condition of SPR. Also, because continuous films have low resistance, the Ag layer can be a minimum thickness.…”

“…At a thickness of 5 nm, the resistivity of the Ag layer was fairly high, because it existed in the form of discontinuous islands. 32,33) The resistivity of the Ag layer drastically decreased at a thickness of 10 nm to 5.8 Ω=□, because it formed an almost continuous film like that of bulk. At a thickness of 20 nm, the sheet resistance was similar to the simulation result using bulk resistivity.…”