Fabrication and characterization of OLEDs

To investigate how AgCl NRs affect OLED properties, conventional bottom-emission OLEDs were fabricated. The following layers were deposited using a thermal evaporator under a base pressure of 1 μTorr. A dielectric (WO₃ 36 nm)/metal (Ag 12 nm)/dielectric (WO₃ 3 nm) structure was used for anode electrodes. Then 4,4′-N,N′-dicarbazole-biphenyl (CBP) doped with 15% WO₃ as a 230-nm hole injection layer (HIL), intrinsic CBP as a 10-nm hole transport layer (HTL), Tris[2-phenylpyridinato-C2, N]iridium(III) Ir(ppy)₃ doped CBP as a 30-nm emissive layer (EML), 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) as a 45-nm hole blocking layer (HBL), LiF as a 1-nm electron injection layer (EIL) and Al as a 100-nm reflective cathode were deposited in sequence.

The J–V characteristics of the OLEDs were measured using a Kiethley 2400 source metre in N₂ ambient. Luminance characteristics of the OLEDs were measured using a calibrated colorimeter (Qbism HEXA50, McScience) in N₂ atmosphere. The EL spectra of OLEDs were measured using a spectrometer (SM240, Spectral Products) equipped with an optical fibre.