Integrated Effects of Near-Field Enhancement-Induced Excitation and Surface Plasmon-Coupled Emission of Elongated Gold Nanocrystals on Fluorescence Enhancement and the Applications in PLEDs

Abstract

Localized surface plasmon resonance (LSPR) field enhancement effects of noble metallic nanoparticles can be exploited to enhance the performance of diverse luminescent materials and devices, in which the spectral proximity plays an important role in increasing near-field enhancement-induced excitation (NFEE) and surface plasmon-coupled emission (SPCE) efficiencies. In this work, we propose a scheme simultaneously utilizing the transversal and longitudinal SPR bands of elongated gold nanocrystals to match with the excitation and emission wavelengths of emitters, respectively, to achieve the most efficient enhancement. To demonstrate the idea, four types of gold nanoparticles (AuNPs, diameter = 20 nm), gold nanorods (AuNRs, length/width = 80/40 nm; 90/30 nm), and gold nano-bipyramids (AuNBPs, length/width = 80/40 nm) were employed as the plasmonic nanoantennas, according to spectral characteristics of the classic poly­(2-methoxy-5-(2′-ethyl-hexoxy)-1,4-phenylene-vinylene) (MEH-PPV) chosen as the emitter. Due to the double SPR bands of both AuNBPs (80/40 nm) and AuNRs (80/40 nm) overlapping well with the excitation and emission wavelengths of MEH-PPV, a maximum 2.2 and 2.1 times enhancement in photoluminescence intensity was observed, respectively. This is attributed to the integrated effects of NFEE and SPCE that synchronously accelerate the excitation and radiation rate as made evident by steady-state and time-resolved photoluminescence measurements. Further, the above plasmonic nanoantennas were incorporated into the polymer light-emitting diodes (PLEDs), in which AuNBPs (80/40 nm)- and AuNRs (80/40 nm)-mediated devices exhibited approximately a 2.3 and 2.1 times enhancement in luminance, and 2.0 and 1.9 times enhancement in luminous efficiency compared with the pristine one, respectively. More notably, it is first demonstrated that the sharp-tip AuNBPs generating a stronger local electric field compared to AuNRs can efficiently enhance PLEDs’ performance, showing a promising prospect for the development of high-performance red and near-infrared electroluminescence devices.

MoS2 Nanoflowers Decorated with Au Nanoparticles for Visible-Light-Enhanced Gas Sensing

“…10 Benefiting from the unique enhancement of light absorption induced by the LSPR effect, noble metal NPs, especially Au NPs have been applied to the field of photoelectric detection. 11 Li et al found that light absorption of the Au−MoS 2 heterojunction could be significantly enhanced due to the LSPR effect, and the photoresponsivity was as high as 22.3 A/ W. 12 significantly increased on account of the plasmonic effect of Au NPs. 13,14 In addition, Au NPs exhibit strong extinction spectra.…”

Surface plasmon–coupled emission imaging for biological applications

“…In SPCE technology, the prism-based SPCE device is most widely utilized and has been applied in multiple analytical and bioanalytical assays, e.g., molecular sensing, immunoassay, and DNA sensing [10,23,28]. In this equipment, fluorescent molecules are located on the thin metal film, which is then attached to the prism with a RI matching fluid.…”

“…However, there is a great demand to achieve higher sensitivity and selectivity with the rapid development of life science. Recently, a surface-enhanced fluorescence technique, referred to as surface plasmon-coupled emission (SPCE), has been widely investigated [7][8][9][10][11]. The high collection efficiency, due to the directed radiation, greatly improves the sensitivity of SPCE.…”

Plasmon-Coupled Directional Emission from Soluplus-Mediated AgAu Nanoparticles for Attomolar Sensing Using a Smartphone

“…13 Recently, research efforts have been devoted to synergize PEF and SPCE into a single hybrid platform. [7][8][9][10][11]14 Generally, the enhancement factor of SPCE substrate is 5−10-fold as compared to traditional luminescence. [7][8][9][10][11]15 Lakowicz and coworkers have demonstrated the significance of silver (Ag) NPs spacer layer engineering on SPCE platform to further augment the enhancement to 60-fold.…”

“…[7][8][9][10][11]14 Generally, the enhancement factor of SPCE substrate is 5−10-fold as compared to traditional luminescence. [7][8][9][10][11]15 Lakowicz and coworkers have demonstrated the significance of silver (Ag) NPs spacer layer engineering on SPCE platform to further augment the enhancement to 60-fold. 15 With this as a preliminary step for combining PEF and SPCE, diverse nanoarchitectures have been explored to further augment the SPCE enhancements.…”