Abstract Conjugated polymers in the solid state usually exhibit low fluorescence quantum yields, which limit their applications many areas such as light-emitting diodes. Despite considerable research efforts, underlying mechanism still remains controversial and elusive. Here, nature properties of excited states archetypal polythiophene are investigated via aggregates suspended solvents with different dielectric constants ( ɛ ). In relatively polar >∼ 3), a yield (QY) 2–5%, similar to bulk...

We synthesized PbS/CdS core/shell quantum dots (QDs) to have functional single-emitter properties for room-temperature, solid-state operation in the telecom O and S bands. Two shell-growth methods—cation exchange successive ionic layer adsorption reaction (SILAR)—were employed prepare QD heterostructures with shells of 2–16 monolayers. QDs were sufficiently bright stable resolve photoluminescence (PL) spectra representing both bands from single nanocrystals using standard detection methods,...

Excitonic energy migration was studied using single molecule spectroscopy of individual conjugated polymer (CP) chains and aggregates. To probe the effect interchain morphology on in CP, tailored morphologies were achieved solvent vapor annealing to construct aggregates, which then with aggregate spectroscopy. We report that highly ordered packing regioregular poly(3-hexylthiophene) (rr-P3HT) enables long-range migration, while disordered regiorandom (rra-P3HT), even aggregates just a few...

Significance Conjugated polymers (CPs) are some of the most attractive organic semiconductors for flexible optoelectronic device applications. The structural and properties CPs dependent on both conformation individual polymer chains interactions between chains. Chemists have sought to control these by creating more planar that can pack tightly together share strong electronic interactions. Single-molecule spectroscopy (SMS) studies a fluorinated CP show backbone fluorination does, in fact,...

Abstract Semiconductor nanostructures capable of emitting from two excited states and thereby producing photoluminescence colours are fundamental potential technological significance. In this limited class nanocrystals, CdSe/CdS core/arm tetrapods exhibit the unusual trait two-colour (red green) multiexcitonic emission, with green emission CdS arms emerging only at high excitation fluences. Here we show that by synthetic shape-tuning, both multi-colour process, blinking photobleaching...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Zhongjian Hu, Simon Tang, Anne Ahlvers, Saiful I. Khondaker, Andre J. Gesquiere; Near-infrared photoresponse sensitization of solvent additive processed poly(3-hexylthiophene)/fullerene solar cells by a low band gap polymer. Appl. Phys. Lett. 30 July 2012; 101 (5): 053308. https://doi.org/10.1063/1.4742143...

Compared to zero-dimensional (0D) semiconductor quantum dots, 2D nanoplatelets (NPLs) offer a spectrally narrow luminescence and superior absorption coefficients, which makes this geometry an attractive candidate for optoelectronic applications. However, optical devices based on NPLs still suffer from nonradiative Auger decay of multiple excitons (MX), limits the efficiency processes, including MX luminescence, electroluminescence, gain. Here, we demonstrate that recombination is strongly...

Abstract The spatial arrangement of the side chains conjugated polymer backbones has critical effects on morphology and electronic photophysical properties corresponding bulk films. effect side‐chain‐distribution density conformation at isolated single‐polymer‐chain level was investigated with regiorandom (rra‐) poly(3‐hexylthiophene) (P3HT) poly(3‐hexyl‐2,5‐thienylene vinylene) (P3HTV). Although pure P3HTV films are known to have low fluorescence quantum efficiencies, we observed a...

Light-emitting nanocrystal quantum dots (QDs) are of high interest for use as down-conversion phosphors and direct emission sources in bulk solid-state devices reliable single photons information science. However, these materials prone to photooxidation that reduces the yield over time. Current commercial applications device architectures prevent oxidation without addressing underlying degradation reactions at level. To instead loss functionality by better synthetic engineering nanoscale...

Spherical semiconductor nanoplatelets, known as quantum shells (QSs), have captured significant interest for their strong suppression of Auger recombination, which leads to long multiexciton lifetimes and wide optical gain bandwidth. Yet, the realization benefits associated with lasing regime using a suitably designed photonic cavity remains elusive. Here, we demonstrate broadly tunable from close-packed films CdS/CdSe/CdS QSs deposited over nanopillar arrays on Si substrates. Wide spectral...

Semiconducting polymer devices have seen tremendous progress in development of material and device designs, while efficiencies made substantial gains. Still, the effect morphology on optoelectronic properties semiconducting polymers is not completely understood even though these materials make up active layer. In this study we use computational methods to simulate different poly(3-hexylthiophene) (P3HT) morphologies, predict their emission spectra, compare them experimentally observed...

Fluorescence-voltage/single particle spectroscopy (F-V/SPS) was employed to study exciton-hole polaron interactions and interfacial charge transfer processes for pure poly(3-hexylthiophene) (P3HT) nanoparticles (NPs) composite P3HT/PC(60)BM NPs in functioning hole-injection devices. F-V/SPS data collected on a particle-by-particle basis reveal an apparent bistability the fluorescence-voltage modulation curves of P3HT [6,6]-phenyl-C(61)-butyric acid methyl ester (PC(60)BM) that is absent NPs....

Structural order of conjugated polymers at different length scales directs the optoelectronic properties corresponding materials; thus it is critical importance to understand and control polymer morphology for successful application these materials in organic optoelectronics. Herein, with aim probing dependence single chain folding on chemical structure rigidness backbones, molecule fluorescence spectroscopy was applied four thiophene-based polymers. These include regioregular...

A strong plasmonic enhancement of photoluminescence (PL) decay rate in quantum dots (QDs) coupled to an array gold‐coated nanocups is demonstrated. CuInS 2 QDs that emit at a wavelength overlaps with the extraordinary optical transmission (EOT) gold nanocup are placed cups as solutions. Time‐resolved PL reveals plasmonically system can be enhanced by more than order magnitude. Using finite‐difference time‐domain (FDTD) simulations, it shown this results from factor ≈100 electric field...

With a tunable size-dependent photoluminescence (PL) over wide infrared wavelength range, lead chalcogenide quantum dots (QDs) have attracted significant scientific and technological interest. Nevertheless, the investigation of intrinsic exciton photophysics at single-QD level has remained challenge. Herein, we present comprehensive study PL properties for individual core/shell PbS/CdS QDs emissive near 1.0 eV. In contrast to sub-meV spectral line widths observed II/VI QDs, are predicted...

Treatment of a Ni‐terminated poly(3‐hexylthiophene) (P3HT), generated in situ from 5‐chloromagnesio‐2‐bromo‐3‐hexylthiophene and Ni(1,3‐bis(diphenylphosphino)propane)Cl 2 , with perylene diimide‐functionalized arylisocyanide monomer effects chain‐extension polymerization to afford donor–acceptor diblock copolymer using single catalyst reaction vessel. The two mechanistically distinct polymerizations proceed controlled, chain growth fashion, allowing the molecular weight both P3HT...

Deterministic coupling between photonic nodes in a quantum network is an essential step toward implementing various technologies. The omnidirectionality of free-standing emitters, however, makes this highly inefficient, particular if the distant are coupled via low numerical aperture (NA) channels such as optical fibers. This limitation requires placing emitters nanoantennas that can direct photons into with very high efficiency. Moreover, to be able scale technologies large number channels,...

Photoluminescence spectroscopy of single CdSe/CdZnS nanoplatelets reveals that shell morphology strongly affects the blinking mechanisms and fine electronic structure splitting.