Primary amines enhance triplet energy transfer from both the band edge and trap state from CdSe nanocrystals

2019 ◽  
Vol 151 (17) ◽  
pp. 174701 ◽  
Author(s):  
Emily M. Rigsby ◽  
Kevin Lee ◽  
Jefferson Sun ◽  
Dmitry A. Fishman ◽  
Ming L. Tang
Keyword(s):  
Energy Transfer ◽  
Band Edge ◽  
Primary Amines ◽  
Cdse Nanocrystals ◽  
Trap State ◽  
Triplet Energy ◽  
Triplet Energy Transfer

ZnS Shells Enhance Triplet Energy Transfer from CdSe Nanocrystals for Photon Upconversion

ACS Photonics ◽  
2018 ◽  
Vol 5 (8) ◽  
pp. 3089-3096 ◽  
Author(s):  
Zhiyuan Huang ◽  
Pan Xia ◽  
Narek Megerdich ◽  
Dmitry A. Fishman ◽  
Valentine I. Vullev ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Cdse Nanocrystals ◽  
Triplet Energy ◽  
Triplet Energy Transfer

scholarly journals Green-to-Blue Triplet Fusion Upconversion Sensitized by Anisotropic CdSe Nanoplatelets

2020 ◽  
Author(s):  
Zachary A. VanOrman ◽  
Alexander S. Bieber ◽  
Sarah Wieghold ◽  
Lea Nienhaus
Keyword(s):  
Energy Transfer ◽  
Quantum Confinement ◽  
Quantum Yields ◽  
Cdse Nanocrystals ◽  
Triplet Energy ◽  
Tunneling Barrier ◽  
Low Efficiency ◽  
Back Transfer ◽  
Triplet Energy Transfer ◽  
Photocatalytic Applications

<p>Green-to-blue photon upconversion bears great potential in photocatalytic applications. However, current hybrid inorganic-organic upconversion schemes utilizing spherical CdSe nanocrystals are often limited by energetic polydispersity, low quantum yields and an additional tunneling barrier resulting from the necessity of surface-passivating inorganic shells. In this contribution, we introduce anisotropic CdSe nanoplatelets as triplet sensitizers. Here, quantum confinement occurs in only one direction, erasing effects stemming from energetic polydispersity. We investigate the triplet energy transfer from the CdSe nanoplatelets to the surface-bound triplet acceptor 9-anthracene carboxylic acid. We further focus on the influence of nanoplatelet stacking and singlet back transfer on the observed upconversion efficiency. We obtain an upconversion quantum yield of 5.4% at a power density of 11 W/cm<sup>2­</sup> using the annihilator 9,10-diphenylanthracene, and a low efficiency threshold <i>I</i><sub>th</sub> of 237 mW/cm<sup>2</sup>. </p>

scholarly journals Green-to-Blue Triplet Fusion Upconversion Sensitized by Anisotropic CdSe Nanoplatelets

2020 ◽  
Author(s):  
Zachary A. VanOrman ◽  
Alexander S. Bieber ◽  
Sarah Wieghold ◽  
Lea Nienhaus
Keyword(s):  
Energy Transfer ◽  
Quantum Confinement ◽  
Quantum Yields ◽  
Cdse Nanocrystals ◽  
Triplet Energy ◽  
Tunneling Barrier ◽  
Low Efficiency ◽  
Back Transfer ◽  
Triplet Energy Transfer ◽  
Photocatalytic Applications

<p>Green-to-blue photon upconversion bears great potential in photocatalytic applications. However, current hybrid inorganic-organic upconversion schemes utilizing spherical CdSe nanocrystals are often limited by energetic polydispersity, low quantum yields and an additional tunneling barrier resulting from the necessity of surface-passivating inorganic shells. In this contribution, we introduce anisotropic CdSe nanoplatelets as triplet sensitizers. Here, quantum confinement occurs in only one direction, erasing effects stemming from energetic polydispersity. We investigate the triplet energy transfer from the CdSe nanoplatelets to the surface-bound triplet acceptor 9-anthracene carboxylic acid. We further focus on the influence of nanoplatelet stacking and singlet back transfer on the observed upconversion efficiency. We obtain an upconversion quantum yield of 5.4% at a power density of 11 W/cm<sup>2­</sup> using the annihilator 9,10-diphenylanthracene, and a low efficiency threshold <i>I</i><sub>th</sub> of 237 mW/cm<sup>2</sup>. </p>

Thymine Dimerization Induced by Oxidative DNA Lesions and Epigenetic Intermediates via Triplet-Triplet Energy Transfer

2020 ◽  
Author(s):  
Mauricio Lineros-Rosa ◽  
Antonio Francés-Monerris ◽  
Antonio Monari ◽  
Miguel Angél Miranda ◽  
Virginie Lhiaubet-Vallet
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Transient Absorption ◽  
Theoretical Calculations ◽  
Dna Lesions ◽  
Transient Absorption Spectroscopy ◽  
Triplet Energy ◽  
Pyrimidine Dimers ◽  
Triplet Energy Transfer ◽  
Dna Nucleobases

Interaction of nucleic acids with light is a scientific question of paramount relevance not only in the understanding of life functioning and evolution, but also in the insurgence of diseases such as malignant skin cancer and in the development of biomarkers and novel light-assisted therapeutic tools. This work shows that the UVA portion of sunlight, not absorbed by canonical DNA nucleobases, can be absorbed by 5-formyluracil (ForU) and 5-formylcytosine (ForC), two ubiquitous oxidative lesions and epigenetic intermediates present in living beings in natural conditions. We measure the strong propensity of these molecules to populate triplet excited states able to transfer the excitation energy to thymine-thymine dyads, inducing the formation of the highly toxic and mutagenic cyclobutane pyrimidine dimers (CPDs). By using steady-state and transient absorption spectroscopy, NMR, HPLC, and theoretical calculations, we quantify the differences in the triplet-triplet energy transfer mediated by ForU and ForC, revealing that the former is much more efficient in delivering the excitation energy and producing the CPD photoproduct. Although significantly slower than ForU, ForC is also able to harm DNA nucleobases and therefore this process has to be taken into account as a viable photosensitization mechanism. The present findings evidence a rich photochemistry crucial to understand DNA photodamage and of potential use in the development of biomarkers and non-conventional photodynamic therapy agents.

Triplet energy transfer in conjugated polymers. II. A polaron theory description addressing the influence of disorder

2008 ◽  
Vol 78 (4) ◽  
Author(s):  
Ivan I. Fishchuk ◽  
Andrey Kadashchuk ◽  
Lekshmi Sudha Devi ◽  
Paul Heremans ◽  
Heinz Bässler ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Conjugated Polymers ◽  
Triplet Energy ◽  
Polaron Theory ◽  
Triplet Energy Transfer

Triplet Energy Transfer Insight in Coordination of Unsaturated Hydrocarbons by d0Bent Metallocenes (Zr, Hf)

2007 ◽  
Vol 111 (43) ◽  
pp. 10928-10937 ◽  
Author(s):  
Galina V. Loukova ◽  
Svetlana E. Starodubova ◽  
Vyatcheslav A. Smirnov
Keyword(s):  
Energy Transfer ◽  
Triplet Energy ◽  
Unsaturated Hydrocarbons ◽  
Triplet Energy Transfer
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