β-(Ethynylbenzoic acid)-substituted push–pull porphyrins: DSSC dyes prepared by a direct palladium-catalyzed alkynylation reaction

Ishida, Masatoshi; Hwang, Deasub; Koo, Young Bean; Sung, Jooyoung; Kim, Dong Young; Sessler, Jonathan L.; Kim, Dongho

doi:10.1039/c3cc44847a

Cited by 51 publications

(33 citation statements)

References 27 publications

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“…19,24 The zinc porphyrin dye (β-(4-ethynylbenzoic acid)-substituted zinc porphyrin, ZnEP1; Figure 5a) recently reported by our lab was chosen as the DS of the DSCs to obtain a power conversion efficiency of 5.9%. 25 Figure 5b shows two routes for charge separation in this device. ZnEP1 anchored on the TiO 2 nanoparticle absorbs 3 and 2.2 eV photons of the Soret and Q-bands (Supplementary Figure S10), respectively, and then transfers an electron into the TiO 2 nanoparticle and a hole into the electrolyte.…”

Section: Distribution Of Quantum Dots In Nanofibermentioning

confidence: 99%

“…DSCs without iQDs exhibited a power conversion efficiency of 5.9%, and those with 500 nM iQDs in the nanofiber exhibited a power conversion efficiency value of 7.4%. Although ZnEP1 has a relatively low absorption coefficient (~1.5 × 10 4 M − 1 cm − 1 ) in the spectral overlap region 25 with the emission of iQD (2.2 eV), the DSCs containing iQDs exhibited a significant increase in power conversion efficiency (25.4%); however, if a dye sensitizer with large absorption coefficient in the spectral overlap region is incorporated into the system, much better device performance will be possible. This improvement in power conversion efficiency is attributed to the increase in shortcircuit photocurrent density (J SC ) caused by an increase in the external quantum efficiency from 2 eV as shown in Figure 5c (see also Table 1).…”

Section: Distribution Of Quantum Dots In Nanofibermentioning

confidence: 99%

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Controlling the spatial distribution of quantum dots in nanofiber for light-harvesting devices

et al. 2015

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The ability to control inter-dot or inter-molecule spacing of functional moieties in solid-state devices has long been studied for both fundamental and technological reasons. In this study, we present a new strategy for controlling the distance between quantum dots (QDs) based on one-dimensional spatial confinement in a polymer nanofiber template. This reliable technique allows for the isolation of QDs at a sufficient distance in a thin film and retains their monomeric character, with distinct spectra from aggregates (~30-nm shift) and monoexponential photoluminescence decay, indicating the suppression of inter-dot interactions. We successfully developed light-harvesting devices by incorporating QDs in nanofibers as an auxiliary light harvester, improving the performance of these devices from 5.9 to 7.4%. This strategy offers a viable path of controlling the arrangements of various functional moieties in solid-state devices. NPG Asia Materials (2015) 7, e202; doi:10.1038/am.2015.76; published online 17 July 2015 INTRODUCTIONThe physicochemical properties of functional moieties in devices such as organic dyes, quantum dots (QDs), graphenes and other nanostructures are different from the properties of their aggregates, 1-7 which frequently deteriorate the performance of the optoelectronic devices (light-emitting diodes, lasers, solar cells, waveguides or photosensors). [8][9][10][11][12][13][14] For instance, QD light-emitting diodes or photovoltaic devices suffer from the inter-dot interactions of aggregates, which cause a spectral shift and a broadening in the photoluminescence of QDs as well as a decrease in the quantum yield. 10,13 Therefore, control of inter-dot spacing is critical in ensuring device performance. [8][9][10]13,15 Researchers have long sought methods to control the spatial distribution of functional moieties in devices and prevent the formation of aggregates, both for fundamental research and the potential technological applications. In solid-state films in particular, it has been challenging to increase film thickness while keeping functional moieties in the monomeric state.Here, we demonstrate a general strategy for controlling the distance between functional moieties based on one-dimensional spatial confinement in a polymeric nanofiber template. One key observation, shown both experimentally and computationally, is that as the radius of a nanofiber template becomes smaller, the distance between moieties increases, thus leading to substantial isolation of each dot. QDs were chosen as a representative functional moiety because they can be easily observed by electron microscopy and because they have a high quantum yield, excellent photostability and long intrinsic lifetime that is distinguishable from their inter-dot energy transfer time (50 ps-2 ns). 15,16 We have fabricated isolated QDs (iQDs) by confining QDs

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Section: Distribution Of Quantum Dots In Nanofibermentioning

confidence: 99%

Section: Distribution Of Quantum Dots In Nanofibermentioning

confidence: 99%

Controlling the spatial distribution of quantum dots in nanofiber for light-harvesting devices

et al. 2015

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“…The structures of 4, 5, 6 were confirmed by TLC, UV-vis and 1 H, 13 C, 11 B NMR spectroscopy, mass-spectrometry. To confirm the conjugates structure the 1 H, 13 C NMR spectra were recorded using heteronuclear correlation methods Cross peaks at 10.63/123.6 ppm were observed in HMBC spectra. These peaks belong to NH hydrogen atom and carbon atom of aniline cycle.…”

Section: Resultsmentioning

confidence: 87%

“…Consequently, NH is a part of aniline moiety, and CH hydrogen is referred to the second and sixth position of the ring. Further, the value of chemical shifts was identified by excluding the set of 1 H and 13 C atoms in the third and fifth positions. The corresponding crosspeak in HSQS is at 7.6/123.6 ppm (Figure 2).…”

Section: Resultsmentioning

confidence: 99%