Light emission through a corrugated metal film: The role of cross-coupled surface plasmon polaritons

Wedge, S.; Hooper, Ian R.; Sage, Ian; Barnes, William

doi:10.1103/physrevb.69.245418

Cited by 55 publications

(39 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One way is to use grating-mediated SPP cross coupling; an appropriate microstructure enables the momentum mismatch between the SPP modes to be overcome, allowing them to interact providing a route to transport energy across the film. 9,10 However, emission mediated via SPP cross-coupling occurs only over a narrow range of emission angles and wavelengths. 9 An alternative method of coupling the SPPs is to ensure that the materials on either side of the metal have the same refractive index, the SPP wave vectors are then degenerate and may couple.…”

mentioning

confidence: 99%

“…9,10 However, emission mediated via SPP cross-coupling occurs only over a narrow range of emission angles and wavelengths. 9 An alternative method of coupling the SPPs is to ensure that the materials on either side of the metal have the same refractive index, the SPP wave vectors are then degenerate and may couple. 11 It is this coupled geometry that we employ here, a dielectric overlayer added to the metal acts to match the effective refractive index sampled by SPP fields.…”

mentioning

confidence: 99%

“…9 An alternative method of coupling the SPPs is to ensure that the materials on either side of the metal have the same refractive index, the SPP wave vectors are then degenerate and may couple.…”

mentioning

confidence: 99%

“…An emitter in the organic layer couples more strongly to the SPP associated with the metal/ organic interface than with the SPP associated with the metal/air interface. 9 The energy coupled into the metal/ organic SPP thus needs to be transported across the metal if it is to emerge as light. One way is to use grating-mediated SPP cross coupling; an appropriate microstructure enables the momentum mismatch between the SPP modes to be overcome, allowing them to interact providing a route to transport energy across the film.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Coupled surface plasmon-polariton mediated photoluminescencefrom a top-emitting organic light-emitting structure

Wedge

Wasey

Barnes

et al. 2004

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

We report strong photoluminescence from a top-emitting organic light-emitting structure where emission takes place through a thin ͑55 nm͒ silver film. We show that this emission is mediated via coupled surface plasmon-polariton modes. Our results show that the addition of a dielectric grating to otherwise planar structures, such as surface-emitting organic light-emitting diodes, may offer a way to increase the external efficiency of top-emitting organic light-emitting diodes. have two advantages over substrate-emitting structures. First, the drive electronics may be integrated into an opaque silicon substrate and second, losses associated with guided modes in the substrate are eliminated. However, a top-emitting OLED does present other problems, notably losses to the surface plasmon-polariton (SPP) modes associated with the metallic cathode. Calculations show that up to 40% of the power that would otherwise be emitted may be lost via this decay channel, 4,5 thus limiting the external quantum efficiency. If some way could be found to recover some of the power lost to these SPPs to light, device efficiency could be improved. One method of coupling SPP modes to light has been the introduction of a periodic microstructure into the metal film, allowing the SPPs to Bragg scatter, 6-8 however, such an approach is demanding in terms of fabrication. Here, we present an alternative in which a microstructured dielectric overlayer is superimposed onto the completed device.A metallic cathode supports two SPP modes, one associated with each metal surface. For a given frequency, these two modes have different in-plane wave vectors (momenta) and so do not interact. An emitter in the organic layer couples more strongly to the SPP associated with the metal/ organic interface than with the SPP associated with the metal/air interface. 9 The energy coupled into the metal/ organic SPP thus needs to be transported across the metal if it is to emerge as light. One way is to use grating-mediated SPP cross coupling; an appropriate microstructure enables the momentum mismatch between the SPP modes to be overcome, allowing them to interact providing a route to transport energy across the film.9,10 However, emission mediated via SPP cross-coupling occurs only over a narrow range of emission angles and wavelengths. 9 An alternative method of coupling the SPPs is to ensure that the materials on either side of the metal have the same refractive index, the SPP wave vectors are then degenerate and may couple.11 It is this coupled geometry that we employ here, a dielectric overlayer added to the metal acts to match the effective refractive index sampled by SPP fields. The coupled SPPs are then scattered to light by a microstructure imposed on the top surface of the dielectric layer.Our experimental structure consisted of a silica substrate spin coated with a 160 nm film of a polymer poly(methylmethacrylate) (PMMA) doped with tris(8-hydroxyquinoline)aluminium ͑Alq 3 ͒ (3% Alq 3 by weight). A 55 nm thick silver film was added by thermal evaporation...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Coupled surface plasmon-polariton mediated photoluminescencefrom a top-emitting organic light-emitting structure

Wedge

Wasey

Barnes

et al. 2004

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

show abstract

“…Finally TM polarized angle dependent photoluminescence ͑PL͒ spectra were obtained by optically exciting the dendrimer containing layer with a 410 nm diode laser and collecting the resulting PL emission, again through the substrate. 18 These data are presented in Fig. 3͑c͒ as a dispersion map with white regions corresponding to areas of high PL emission.…”

Section: -2mentioning

confidence: 99%

Surface plasmon-polariton mediated emission from phosphorescent dendrimer light-emitting diodes

Yates

Samuel

Burn

et al. 2006

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

We present experimental results showing electroluminescence from a dendrimer based organic light-emitting diode ͑OLED͒ mediated via surface plasmon polariton ͑SPP͒ modes. A combination of angle dependent electroluminescence, photoluminescence, and reflectance measurements is used to identify emission originating from the guided modes of the device. It is found that the SPP modes, which are usually nonradiative, are coupled to light by a wavelength scale periodic microstructure. It is demonstrated that the necessary microstructure can be readily fabricated by solvent-assisted micromoulding. Our results indicate that such an approach may offer a means to increase the efficiency of dendrimer based OLEDs. © 2006 American Institute of Physics. ͓DOI: 10.1063/1.2193795͔While organic light-emitting diodes ͑OLEDs͒ have shown much promise in display applications, their device architecture is such that excitons created within the organic emissive layer may relax via a number of decay routes. These routes may include some or all of the following: surface plasmon-polariton ͑SPP͒ modes associated with the metallic cathode/organic interface, waveguided modes within the substrate and organic emissive layers, and Joule heating of the cathode. As a consequence of these decay routes, the intensity of the emitted light from these devices into the far field may be significantly impaired. 1,2 Improving the efficiency with which light is extracted from these structures is thus a key concern.One class of material that has shown great promise as highly efficient organic emitters are phosphorescent iridium ͑III͒ complex cored dendrimers. 3,4 Dendrimers allow fine tuning of photophysical properties by independent variation of core, dendrons and dendrimer generation. [5][6][7] The combination of high dendrimer light-emitting diode ͑DLED͒ efficiency, molecular level engineering of the physical properties, and their suitability for solution processing makes these materials extremely attractive for industrial fabrication processes. However, DLEDs using phosphorescent dendrimer emitters also suffer losses to SPP and waveguided modes, thus diminishing the overall device efficiency. 2 The very high DLED internal quantum efficiency ͑ϳ80% ͒ of the best dendrimer materials indicates that significant increases in light output from these OLEDs must be sought via increases in the optical outcoupling efficiency of these devices, and it is just such an approach that we pursue here. In particular, we concentrate upon recovering energy lost from the emissive layer to SPP modes as useful light in the far field by modifying the device geometry, an aspect of DLED devices that has not so far been investigated experimentally.SPPs are guided transverse magnetic ͑TM͒ polarized electromagnetic surface modes that occur at the interface between a metal and a dielectric. SPP modes have electromagnetic fields that decay exponentially into both the bounding metal and dielectric media and, as they possess a greater momentum than free space photons of the same frequency...

show abstract

Device Efficiency of Organic Light‐Emitting Diodes

Brütting¹,

Frischeisen²

2012

Physics of Organic Semiconductors

View full text Add to dashboard Cite

Light emission through a corrugated metal film: The role of cross-coupled surface plasmon polaritons

Cited by 55 publications

References 32 publications

Coupled surface plasmon-polariton mediated photoluminescencefrom a top-emitting organic light-emitting structure

Coupled surface plasmon-polariton mediated photoluminescencefrom a top-emitting organic light-emitting structure

Surface plasmon-polariton mediated emission from phosphorescent dendrimer light-emitting diodes

Device Efficiency of Organic Light‐Emitting Diodes

Contact Info

Product

Resources

About