Manipulating Energy and Spin for Photon Up- and Downconversion

By Sean Roberts

Material Science and Engineering, University of Texas at Austin, Austin, TX

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Abstract

The negligible spin-orbit coupling in many organic molecules creates opportunities to alter the energy of excited electrons by manipulating their spin. In particular, molecules with a large exchange splitting have garnered interest due to their potential to undergo singlet fission (SF), a process where a molecule in a high-energy spin-singlet state shares its energy with a neighbor, placing both in a low-energy spin-triplet state. When incorporated into photovoltaic and photocatalytic systems, SF can offset losses from carrier thermalization, which account for ~50% of the energy dissipated by these technologies. Likewise, compounds that undergo SF’s inverse, triplet fusion (TF), can be paired with infrared absorbers to create structures that upconvert infrared into visible light. In this presentation, I will review our group’s efforts to create organic:inorganic structures that use SF and TF for improved light harvesting and photon upconversion.

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Researchers should cite this work as follows:

  • Sean Roberts (2018), "Manipulating Energy and Spin for Photon Up- and Downconversion," https://nanohub.org/resources/29296.

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Location

4102 Brown Hall, Purdue University, West Lafayette, IN

Manipulating Energy and Spin for Photon Up- and Downconversion
  • Manipulating Energy & Spin for Photon Up- & Downconversion 1. Manipulating Energy & Spin for… 0
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  • Molecular Semiconductors 2. Molecular Semiconductors 124.82482482482483
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  • The Roberts Group: Areas of Research 3. The Roberts Group: Areas of Re… 196.26292959626295
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  • Acknowledgements 4. Acknowledgements 330.83083083083085
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  • Singlet Fission 5. Singlet Fission 388.45512178845513
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  • Using Singlet Fission in a Solar Cell 6. Using Singlet Fission in a Sol… 649.71638304971646
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  • Perylene Diimides 7. Perylene Diimides 791.22455789122455
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  • Perylene Diimides: Crystallochromy 8. Perylene Diimides: Crystalloch… 954.98832165498834
    00:00/00:00
  • Perylene Diimides: Crystallochromy 9. Perylene Diimides: Crystalloch… 1041.1411411411411
    00:00/00:00
  • Singlet Fission: Perylene Diimides 10. Singlet Fission: Perylene Diim… 1073.8405071738405
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  • Perylene Diimides: Vapor Deposited Films 11. Perylene Diimides: Vapor Depos… 1183.24991658325
    00:00/00:00
  • Transient Absorption Spectroscopy 12. Transient Absorption Spectrosc… 1227.660994327661
    00:00/00:00
  • PDI Excited State Dynamics 13. PDI Excited State Dynamics 1322.4224224224224
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  • Triplet Sensitization 14. Triplet Sensitization 1403.7370704037371
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  • Magnetic Field: Emission Modulation 15. Magnetic Field: Emission Modul… 1515.0483817150484
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  • Fission Rates: Experiment vs. Theory 16. Fission Rates: Experiment vs. … 1636.302969636303
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  • Singlet Fission: Energetic Driving Force 17. Singlet Fission: Energetic Dri… 1834.7347347347347
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  • Extracting Triplet Excitons 18. Extracting Triplet Excitons 1933.4668001334669
    00:00/00:00
  • Why do the Triplets Decay Quickly? 19. Why do the Triplets Decay Quic… 1973.3066399733068
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  • Diabatic State Mixing 20. Diabatic State Mixing 2040.8742075408743
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  • Building New PDIs 21. Building New PDIs 2148.6820153486819
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  • Organic-Inorganic Energy Transfer 22. Organic-Inorganic Energy Trans… 2192.7594260927594
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  • Organic-Inorganic Energy Transfer 23. Organic-Inorganic Energy Trans… 2335.4354354354355
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  • Acene-Functionalized Quantum Dots 24. Acene-Functionalized Quantum D… 2438.4718051384721
    00:00/00:00
  • PbS:2-CP Transient Absorption Spectra 25. PbS:2-CP Transient Absorption … 2513.546880213547
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  • Triplet Formation Kinetics 26. Triplet Formation Kinetics 2548.3817150483819
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  • What is the Intermediate? 27. What is the Intermediate? 2578.1114447781115
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  • Constrained DFT: Identifying Triplet States 28. Constrained DFT: Identifying T… 2629.1958625291959
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  • Surface State Mediated Triplet Transfer 29. Surface State Mediated Triplet… 2681.9819819819822
    00:00/00:00
  • Enhancing Triplet Energy Transfer 30. Enhancing Triplet Energy Trans… 2741.0410410410414
    00:00/00:00
  • Enhancing Transfer with Proper Linker Choice 31. Enhancing Transfer with Proper… 2786.8535201868535
    00:00/00:00
  • Extracting Triplets into Silicon 32. Extracting Triplets into Silic… 2896.1961961961965
    00:00/00:00
  • Extracting Triplets into Silicon 33. Extracting Triplets into Silic… 2953.21988655322
    00:00/00:00
  • Even Order Nonlinear Spectroscopy 34. Even Order Nonlinear Spectrosc… 3010.744077410744
    00:00/00:00
  • Electronic Sum Frequency Generation 35. Electronic Sum Frequency Gener… 3065.765765765766
    00:00/00:00
  • ESFG Dependence on Film Thickness 36. ESFG Dependence on Film Thickn… 3120.286953620287
    00:00/00:00
  • Extracting the Buried Density of States 37. Extracting the Buried Density … 3140.7741074407741
    00:00/00:00
  • ESFG: PDI Thin Films 38. ESFG: PDI Thin Films 3149.5829162495829
    00:00/00:00
  • Strain-Induced Structural Changes 39. Strain-Induced Structural Chan… 3182.8161494828164
    00:00/00:00
  • Strain-Induced Structural Changes 40. Strain-Induced Structural Chan… 3202.4691358024693
    00:00/00:00
  • PDIs on Silicon 41. PDIs on Silicon 3247.6476476476478
    00:00/00:00
  • PDIs on Silicon: Exciton Quenching 42. PDIs on Silicon: Exciton Quenc… 3284.9516182849516
    00:00/00:00
  • Summary & Future Work 43. Summary & Future Work 3343.0430430430433
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  • Find out More at: GreenEnergyATX.org 44. Find out More at: GreenEnergyA… 3366.1661661661665
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  • Thank You! 45. Thank You! 3396.4631297964634
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