Electroluminescent Polyhedral Oligomeric Silsesquioxane-Based Nanoparticle

Abstract

A polyhedral oligomeric silsesquioxane (POSS)-based blue light electroluminescent nanoparticle, POSS-FL3, which contains a terfluorene chromophore on each of its eight arms, was easily prepared via the hydrosilation reaction between octakis(dimethylsiloxy)silsesquioxane and an allyl-functionalized terfluorene chromophore that emits blue light as a result of photo- or electroexcitation. POSS-FL3 exhibits good solubility in common organic solvents, such as chloroform, THF, toluene, p-xylene, and chlorobenzene, and good film-forming properties on a quartz plate or an indium tin oxide (ITO) plate; i.e., it has good solution processing properties. The good spectral overlap of the maximum absorption wavelength (391 nm in THF solution) of poly(dihexylfluorene) with the maximum emission wavelengths (394 nm in THF solution) of POSS-FL3 suggests that POSS-FL3 can be used as a dopant of blue light-emissive conjugated polymers such as polyfluorenes to increase their quantum efficiencies through energy transfer. A single-layered electroluminescence (EL) device with the configuration of ITO/PEDOT:PSS/POSS-FL3/Ca (500 nm)/Al (800 nm) was fabricated, with maximum EL peaks at 400, 422, and 464 nm. The external quantum efficiency (EQE) of the POSS-FL3 device (0.0164%) was found to be higher than that of poly(dihexylfluorene) devices in EL devices (0.0095%). Surprisingly, the external quantum efficiencies in EL devices of POSS-FL3 doped poly(dihexylfluorene) blends were found to be about 4−8 times greater than that of poly(dihexylfluorene).

Green emitting polyhedral oligomeric silsesquioxanes / poly(phenylene vinylene) derivative materials for highly efficient organic light emitting diodes (OLEDs)

“…The performance of diodes using the POSS-(DPOC 10 -PPV) is obviously improved as compared to devices using the pristine polymer. Previous investigations of POSS based diodes have suggested the improvement of the light emission would be due to the fact that POSS units separate the polymer chains, and reducing aggregation effects [31][32][33]. However, such a process would imply a blue shift of the PL spectrum in POSS-polymer hybrid material, which is not observed in our samples.…”

Energy Flow in a Purpose‐Built Cascade Molecule Bearing Three Distinct Chromophores Attached to the Terminal Acceptor

“…Tetrahydrofuran was distilled over sodium and benzophenone. Samples of 4,4‐difluoro‐1,3,5,7,8‐pentamethyl‐2,4‐diethyl‐4‐bora‐3a,4a‐diaza‐s‐indacene ( 1 ),52 1‐ethynyl‐8‐propargylicalcoholpyrene ( 3 ),53 3‐ethynylperylene ( 4 ),54 and 2‐bromo‐9,9‐di‐ n ‐butyl‐9H‐fluorene ( 5 ),55 were prepared and purified according to literature procedures. All reactions were carried out under argon using Schlenk‐tube and vacuum‐line techniques.…”

Self-assembly behavior and photoluminescence property of bispyrenyl-POSS nanoparticle hybrid

“…Recently, many literatures reported that the bulky organic and inorganic hybrid POSS nanoparticles could effectively reduce the aggregations of photoluminescence units in the active layers of organic molecule and polymer light-emitting diode devices (OLED [11][12][13][14][15][16] and PLED [17][18][19][20][21][22]). Furthermore, POSS molecules can be regarded as core-shell colloids with solvated alkyl or aryl shells to disperse insoluble siloxane cores in solution [23][24][25][26][27][28][29][30].…”