Acene

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Sean T. Roberts - One of the best experts on this subject based on the ideXlab platform.

  • Surface States Mediate Triplet Energy Transfer in Nanocrystal–Acene Composite Systems
    Journal of the American Chemical Society, 2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis(triisopropylsilylethynyl)pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. Thi...

  • surface states mediate triplet energy transfer in nanocrystal Acene composite systems
    Journal of the American Chemical Society, 2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis(triisopropylsilylethynyl)pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. Thi...

  • Surface States Mediate Triplet Energy Transfer in Nanocrystal–Acene Composite Systems
    2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis­(triisopropylsilylethynyl)­pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. This intermediate persists for ∼100 ns before evolving to produce TIPS-pentAcene triplet excitons. Analysis of transient absorption lineshapes suggests this intermediate corresponds to charge carriers localized at the PbS nanocrystal surface. This hypothesis is supported by constrained DFT calculations that find a large number of spin-triplet states at PbS NC surfaces. Though some of these states can facilitate triplet transfer, others serve as traps that hinder it. Our results highlight that nanocrystal surfaces play an active role in mediating energy transfer to bound Acene ligands and must be considered when optimizing composite NC-based materials for photon upconversion, photocatalysis, and other optoelectronic applications

Kenneth D. Jordan - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of theoretical approaches for describing the interaction of water with linear Acenes.
    The Journal of Physical Chemistry A, 2011
    Co-Authors: Glen R. Jenness, Ozan Karalti, W. A. Al-saidi, Kenneth D. Jordan
    Abstract:

    The interaction of a water monomer with a series of linear Acenes (benzene, anthrAcene, pentAcene, heptAcene, and nonAcene) is investigated using a wide range of electronic structure methods, including several “dispersion”-corrected density functional theory (DFT) methods, several variants of the random phase approximation (RPA), DFT-based symmetry-adapted perturbation theory with density fitting (DF-DFT-SAPT), MP2, and coupled-cluster methods. The DF-DFT-SAPT calculations are used to monitor the evolution of the electrostatics, exchange-repulsion, induction, and dispersion contributions to the interaction energies with increasing Acene size and also provide the benchmark data against which the other methods are assessed.

  • benchmark calculations of water Acene interaction energies extrapolation to the water graphene limit and assessment of dispersion corrected dft methods
    Physical Chemistry Chemical Physics, 2010
    Co-Authors: Glen R. Jenness, Ozan Karalti, Kenneth D. Jordan
    Abstract:

    In a previous study (J. Phys. Chem. C, 2009, 113, 10242-10248) we used density functional theory based symmetry-adapted perturbation theory (DFT-SAPT) calculations of water interacting with benzene (C(6)H(6)), coronene (C(24)H(12)), and circumcoronene (C(54)H(18)) to estimate the interaction energy between a water molecule and a graphene sheet. The present study extends this earlier work by use of a more realistic geometry with the water molecule oriented perpendicular to the Acene with both hydrogen atoms pointing down. We also include results for an intermediate C(48)H(18) Acene. Extrapolation of the water-Acene results gives a value of -3.0 +/- 0.15 kcal mol(-1) for the binding of a water molecule to graphene. Several popular dispersion-corrected DFT methods are applied to the water-Acene systems and the resulting interacting energies are compared to results of the DFT-SAPT calculations in order to assess their performance.

  • Benchmark calculations of water–Acene interaction energies: Extrapolation to the water–graphene limit and assessment of dispersion–corrected DFT methods
    Physical Chemistry Chemical Physics, 2010
    Co-Authors: Glen R. Jenness, Ozan Karalti, Kenneth D. Jordan
    Abstract:

    In a previous study (J. Phys. Chem. C, 2009, 113, 10242-10248) we used density functional theory based symmetry-adapted perturbation theory (DFT-SAPT) calculations of water interacting with benzene (C(6)H(6)), coronene (C(24)H(12)), and circumcoronene (C(54)H(18)) to estimate the interaction energy between a water molecule and a graphene sheet. The present study extends this earlier work by use of a more realistic geometry with the water molecule oriented perpendicular to the Acene with both hydrogen atoms pointing down. We also include results for an intermediate C(48)H(18) Acene. Extrapolation of the water-Acene results gives a value of -3.0 +/- 0.15 kcal mol(-1) for the binding of a water molecule to graphene. Several popular dispersion-corrected DFT methods are applied to the water-Acene systems and the resulting interacting energies are compared to results of the DFT-SAPT calculations in order to assess their performance.

Jon A. Bender - One of the best experts on this subject based on the ideXlab platform.

  • Surface States Mediate Triplet Energy Transfer in Nanocrystal–Acene Composite Systems
    Journal of the American Chemical Society, 2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis(triisopropylsilylethynyl)pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. Thi...

  • surface states mediate triplet energy transfer in nanocrystal Acene composite systems
    Journal of the American Chemical Society, 2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis(triisopropylsilylethynyl)pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. Thi...

  • Surface States Mediate Triplet Energy Transfer in Nanocrystal–Acene Composite Systems
    2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis­(triisopropylsilylethynyl)­pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. This intermediate persists for ∼100 ns before evolving to produce TIPS-pentAcene triplet excitons. Analysis of transient absorption lineshapes suggests this intermediate corresponds to charge carriers localized at the PbS nanocrystal surface. This hypothesis is supported by constrained DFT calculations that find a large number of spin-triplet states at PbS NC surfaces. Though some of these states can facilitate triplet transfer, others serve as traps that hinder it. Our results highlight that nanocrystal surfaces play an active role in mediating energy transfer to bound Acene ligands and must be considered when optimizing composite NC-based materials for photon upconversion, photocatalysis, and other optoelectronic applications

Tamar Goldzak - One of the best experts on this subject based on the ideXlab platform.

  • Surface States Mediate Triplet Energy Transfer in Nanocrystal–Acene Composite Systems
    Journal of the American Chemical Society, 2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis(triisopropylsilylethynyl)pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. Thi...

  • surface states mediate triplet energy transfer in nanocrystal Acene composite systems
    Journal of the American Chemical Society, 2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis(triisopropylsilylethynyl)pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. Thi...

  • Surface States Mediate Triplet Energy Transfer in Nanocrystal–Acene Composite Systems
    2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis­(triisopropylsilylethynyl)­pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. This intermediate persists for ∼100 ns before evolving to produce TIPS-pentAcene triplet excitons. Analysis of transient absorption lineshapes suggests this intermediate corresponds to charge carriers localized at the PbS nanocrystal surface. This hypothesis is supported by constrained DFT calculations that find a large number of spin-triplet states at PbS NC surfaces. Though some of these states can facilitate triplet transfer, others serve as traps that hinder it. Our results highlight that nanocrystal surfaces play an active role in mediating energy transfer to bound Acene ligands and must be considered when optimizing composite NC-based materials for photon upconversion, photocatalysis, and other optoelectronic applications

Troy Van Voorhis - One of the best experts on this subject based on the ideXlab platform.

  • Surface States Mediate Triplet Energy Transfer in Nanocrystal–Acene Composite Systems
    Journal of the American Chemical Society, 2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis(triisopropylsilylethynyl)pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. Thi...

  • surface states mediate triplet energy transfer in nanocrystal Acene composite systems
    Journal of the American Chemical Society, 2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis(triisopropylsilylethynyl)pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. Thi...

  • Surface States Mediate Triplet Energy Transfer in Nanocrystal–Acene Composite Systems
    2018
    Co-Authors: Jon A. Bender, Emily K. Raulerson, Tamar Goldzak, Pan Xia, Troy Van Voorhis, Ming Lee Tang, Sean T. Roberts
    Abstract:

    Hybrid organic:inorganic materials composed of semiconductor nanocrystals functionalized with Acene ligands have recently emerged as a promising platform for photon upconversion. Infrared light absorbed by a nanocrystal excites charge carriers that can pass to surface-bound Acenes, forming triplet excitons capable of fusing to produce visible radiation. To fully realize this scheme, energy transfer between nanocrystals and Acenes must occur with high efficiency, yet the mechanism of this process remains poorly understood. To improve our knowledge of the fundamental steps involved in nanoparticle:Acene energy transfer, we used ultrafast transient absorption to investigate excited electronic dynamics of PbS nanocrystals chemically functionalized with 6,13-bis­(triisopropylsilylethynyl)­pentAcene (TIPS-pentAcene) ligands. We find photoexcitation of PbS does not lead to direct triplet energy transfer to surface-bound TIPS-pentAcene molecules but rather to the formation of an intermediate state within 40 ps. This intermediate persists for ∼100 ns before evolving to produce TIPS-pentAcene triplet excitons. Analysis of transient absorption lineshapes suggests this intermediate corresponds to charge carriers localized at the PbS nanocrystal surface. This hypothesis is supported by constrained DFT calculations that find a large number of spin-triplet states at PbS NC surfaces. Though some of these states can facilitate triplet transfer, others serve as traps that hinder it. Our results highlight that nanocrystal surfaces play an active role in mediating energy transfer to bound Acene ligands and must be considered when optimizing composite NC-based materials for photon upconversion, photocatalysis, and other optoelectronic applications

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