Enhancement of Alq3 fluorescence by nanotextured silver films deposited on porous alumina substrates

Abstract

Enhanced photoluminescence was found in tris-8-hydroxyquinoline aluminum deposited onto nanotextured silver films with porous alumina substrates. The surface-enhanced Raman signals and shortened lifetimes suggested the presence of enhanced local electromagnetic field due to the plasmon resonance of nanotextured silver films. The photoluminescence enhancement was attributed to the increase in absorption and quantum yield. The authors analyzed the increase in quantum yield and found that the highest quantum yield was enhanced by 2.3 times compared with the samples based on flat Ag film with the same thickness. The enhancement of quantum yield has potential applications in electro-optic devices.

Surface plasmon-enhanced electroluminescence in organic light-emitting diodes incorporating Au nanoparticles

“…26 It has been reported that the coupling process between SPs and radiated light is much faster than spontaneous recombination of excitons, and the exciton lifetime in SP-enhanced devices should be much decreased. 17,27 Here, time-resolved PL spectra of a 50 nm-thick Alq 3 layer on PEDOT:PSS coated ITO glass substrates with and without Au NPs were measured as shown in Fig. 3.…”

Effect of gold nanorods and nanocubes on electroluminescent performances in organic light-emitting diodes and its working mechanism

“…Using Au NRs near the EML of DCJTB (0.5 nm) makes DCJTB's lifetime obviously decrease to 3.9 ns (figure 7(b)) and this result is consistent with other's reported result. 24 The increase in the spontaneous emission rate of DCJTB demonstrates an efficient coupling between Au NRs-induced SPs and the excitons.…”

“…24 In order to explore the influence of the radiative decay rate of the exciton on device performance, we measured time-resolved transient photoluminescence decay curves of Ir(MDQ) 2 (acac) (0.1 nm) with and without Au NRs. As shown in figure 7(a), the PL lifetime of pure Ir(MDQ) 2 (acac) (at 600 nm) without Au NRs is 1.075 µs and it maintains 1.072 µs with the use of Au NRs, exhibiting no alteration at all.…”

Surface-plasmon-enhanced photoluminescence from metal-capped Alq3 thin Films

“…[5][6][7]10 In most experiments, the photoluminescence ͑PL͒ has been collected in the backward or forward direction. 1,6,7,9 Part of the increase in the luminous intensity may be attributed to reflection of light from the metal "mirror" in the backward direction, and/or to enhanced forward ͑and backward͒ scattering of the PL due to the roughness of the metal. Only light within a small emission cone is able to escape into the air at a dielectric/air interface due to total internal reflection.…”

“…Recently, surface-plasmon ͑SP͒-mediated emission has been produced from semiconductors and organic films by capping them with a thin layer of metal. [1][2][3][4][5][6][7][8][9] When the metal layer is placed within the near-field of the emissive layer and when the energy gap of the semiconductor is comparable to the SP energy at the metal-dielectric surface, resonant coupling to the SP mode greatly enhances the spontaneous recombination rate in the semiconductor. However, with a metal layer present, up to 40% of the device's power is lost to SP modes.…”