TY  - JOUR
A1  - Heydari, Esmaeil
A1  - Pastoriza-Santos, Isabel
A1  - Liz-Marzan, Luis M.
A1  - Stumpe, Joachim
T1  - Nanoplasmonically-engineered random lasing in organic semiconductor thin films
JF  - Nanoscale horizons
N2  - We demonstrate plasmonically nano-engineered coherent random lasing and stimulated emission enhancement in a hybrid gainmedium of organic semiconductors doped with core-shell plasmonic nanoparticles. The gain medium is composed of a 300 +/- 2 nm thin waveguide of an organic semiconductor, doped with 53 nm gold nanoparticle cores, isolated within silica shells. Upon loading the nanoparticles, the threshold of amplified spontaneous emission is reduced from 1.75 mu J cm(-2) x 10(2) for an undoped gain medium, to 0.35 mu J cm(-2) x 10(2) for a highly concentrated gain medium, and lasing spikes narrower than 0.1 nm are obtained. Most importantly, selection of silica shells with thicknesses of 10, 17 and 21 nm enables engineering of the plasmon-exciton energy coupling and consequently tuning of the laser slope efficiency. With this approach, the slope efficiency is increased by two times by decreasing the silica shell from 21 nm down to 10 nm, due to the enhancement of the localized electric field.
Y1  - 2017
U6  - https://doi.org/10.1039/c7nh00054e
SN  - 2055-6756
SN  - 2055-6764
VL  - 2
SP  - 261
EP  - 266
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Heydari, Esmaeil
A1  - Pastoriza-Santos, Isabel
A1  - Flehr, Roman
A1  - Liz-Marzan, Luis M.
A1  - Stumpe, Joachim
T1  - Nanoplasmonic enhancement of the emission of semiconductor polymer composites
JF  - The journal of physical chemistry : C, Nanomaterials and interfaces
N2  - We report on the influence of localized surface plasmon resonance excitation of Au@SiO2 core-shell nanoparticles on the amplified spontaneous emission of a semiconductor polymer composite (F8BT/MEH-PPV). Au@SiO2 nanoparticles are compatible with the donor-acceptor polymer matrix and get uniformly distributed within the whole polymer film. The plasmon resonance band of the nanoparticles correlates with both the emission and excitation spectra of the polymer composite, as well as with the donor emission and acceptor excitation spectra. We demonstrate that resonantly excited Au@SiO2 nanoparticles enhance the amplified spontaneous emission and the modal gain of the polymer films. The measurement of influential factors reveals that the emission is enhanced predominantly by the increase of acceptor excitation rate, which is accompanied by depletion of the FRET efficiency and increase of quantum yield. The enhancement factor is increased by both introducing a higher loading of plasmonic nanoparticles in the polymer film and increasing the excitation energy. This work shows that these plasmonic nanoantennas are able to enhance the stimulated emission of semiconductor polymers by improving the size mismatch between the excitation light and the emitting polymer.
Y1  - 2013
U6  - https://doi.org/10.1021/jp404068m
SN  - 1932-7447
VL  - 117
IS  - 32
SP  - 16577
EP  - 16583
PB  - American Chemical Society
CY  - Washington
ER  -