Photoluminescence decay rate engineering of CdSe quantum dots in ensemble arrays embedded with gold nano-antennae

Abstract

We discuss experimental results on the ability to significantly tune the photoluminescence decay rates of CdSe quantum dots embedded in an ordered template, using lightly doped small gold nanoparticles (nano-antennae), of relatively low optical efficiency. We observe both enhancement and quenching of photoluminescence intensity of the quantum dots varying monotonically with increasing volume fraction of added gold nanoparticles, with respect to undoped quantum dot arrays. However, the corresponding variation in lifetime of photoluminescence spectra decay shows a hitherto unobserved, non-monotonic variation with gold nanoparticle doping. We also demonstrate that Purcell effect is quite effective for the larger (5 nm) gold nano-antenna leading to more than four times enhanced radiative rate at spectral resonance, for largest doping and about 1.75 times enhancement for off-resonance. Significantly for spectral off-resonance samples, we could simultaneously engineer reduction of non-radiative decay rate along with increase of radiative decay rate. Non-radiative decay dominates the system for the smaller (2 nm) gold nano-antenna setting the limit on how small these plasmonic nano-antennae could be to be effective in engineering significant enhancement in radiative decay rate and, hence, the overall quantum efficiency of quantum dot based hybrid photonic assemblies. V C 2013 AIP Publishing LLC.

Plasmon-mediated emergence of collective emission and enhanced quantum efficiency in quantum dot films

“…Colloidal quantum dots (CQDs) are specially attractive in this context since they can be prepared over a wide spectral range in highly monodisperse form and can also be easily assembled in to compact mono/multilayered films of arbitrary density using simple methods [6][7][8]. While the optical [9][10][11] and electro-optical properties [12][13][14][15] of these materials have been well studied, the necessity to push the limits of their quantum efficiencies (QE) for various applications has intensified research in this direction [16][17][18][19][20][21][22][23][24][25][26]. Some theoretical studies [27][28][29][30] in the recent past have suggested the possibility of obtaining the strong coupling and collective emission (CE) from an ensemble of quantum emitters like CQDs, mediated by plasmons.…”

First-principles modeling of electromagnetic scattering by discrete and discretely heterogeneous random media

“…The first studies of electromagnetic scattering by random three-dimensional multi-particle groups based on direct computer solutions of the MMEs [245][246][247][248] exploited the frequencydomain multi-sphere method [249][250][251][252][253] which can be considered a particular case of the STMM. More recently, other numerical solvers of the MMEs have been used, such as the PSTDM and its variations [254][255][256][257][258], the DDA [259][260][261][262][263][264][265][266][267][268][269][270][271][272][273][274], the FDTDM [275][276][277], and the hybrid finite element-boundary integral-characteristic basis function method [278][279][280][281]. However, the STMM appears to have been the most frequently used technique [268,.…”

Radiative decay of an emitter due to non-Markovian interactions with dissipating matter

“…This divergence of SERS from first-principle theoretical predictions has been widening for decades, as the reported SERS enhancements grew from 10 4 to 10 14 [19][20][21]. Meanwhile, anomalous enhancements of spontaneous emission near fully absorbing metal nanoparticles less than 10 nm in dimensions, have also been reported [22][23][24][25][26].…”