Charge Transport in Organic Semiconducting Crystals Exhibiting TADF: Insight from Quantum Chemical Calculations
Luminophores featuring thermally activated delayed fluorescence (TADF) are the workhorses of the third- and fourth-generation OLEDs. While these compounds have usually been used as dopants embedded in the host, non-doped TADF OLEDs have recently shown significant progress as well and have attained p...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-12-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/13/1/55 |
| _version_ | 1797444128411222016 |
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| author | Andrey Y. Sosorev Dmitry I. Dominskiy Nikita O. Dubinets |
| author_facet | Andrey Y. Sosorev Dmitry I. Dominskiy Nikita O. Dubinets |
| author_sort | Andrey Y. Sosorev |
| collection | DOAJ |
| description | Luminophores featuring thermally activated delayed fluorescence (TADF) are the workhorses of the third- and fourth-generation OLEDs. While these compounds have usually been used as dopants embedded in the host, non-doped TADF OLEDs have recently shown significant progress as well and have attained performances comparable to those of the host-dopant systems. For efficient operation of non-doped OLEDs, the charge transport in neat films and single crystals of TADF luminophores is important; however, this issue was nearly unexplored theoretically. In the current study, we calculated the charge-carrier mobilities in four single crystals of TADF luminophores that have different molecular packing motifs. Specifically, in one of them both the donor and acceptor moieties form uniform π-stacks, while in the others the donors (acceptors) show alternating lateral shifts along the stacks; the difference in the molecular packing resulted in the difference in the transfer integrals between the molecules. The reorganization energies differed as well by up to four times for the studied crystals. As a result, the charge mobilities varied from 0.001 to ~0.3 cm<sup>2</sup>/(V∙s), with the largest being predicted for the crystal of the luminophore that consisted of a rigid donor and acceptor. We anticipate that the results obtained will be useful in the design of TADF luminophores for non-doped OLEDs, OLETs, and other organic light-emitting devices. |
| first_indexed | 2024-03-09T13:07:07Z |
| format | Article |
| id | doaj.art-da20e29185e74282a695cc75838477e1 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-03-09T13:07:07Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-da20e29185e74282a695cc75838477e12023-11-30T21:47:23ZengMDPI AGCrystals2073-43522022-12-011315510.3390/cryst13010055Charge Transport in Organic Semiconducting Crystals Exhibiting TADF: Insight from Quantum Chemical CalculationsAndrey Y. Sosorev0Dmitry I. Dominskiy1Nikita O. Dubinets2Enikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Sciences, Profsoyuznaya 70, Moscow 117393, RussiaEnikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Sciences, Profsoyuznaya 70, Moscow 117393, RussiaEnikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Sciences, Profsoyuznaya 70, Moscow 117393, RussiaLuminophores featuring thermally activated delayed fluorescence (TADF) are the workhorses of the third- and fourth-generation OLEDs. While these compounds have usually been used as dopants embedded in the host, non-doped TADF OLEDs have recently shown significant progress as well and have attained performances comparable to those of the host-dopant systems. For efficient operation of non-doped OLEDs, the charge transport in neat films and single crystals of TADF luminophores is important; however, this issue was nearly unexplored theoretically. In the current study, we calculated the charge-carrier mobilities in four single crystals of TADF luminophores that have different molecular packing motifs. Specifically, in one of them both the donor and acceptor moieties form uniform π-stacks, while in the others the donors (acceptors) show alternating lateral shifts along the stacks; the difference in the molecular packing resulted in the difference in the transfer integrals between the molecules. The reorganization energies differed as well by up to four times for the studied crystals. As a result, the charge mobilities varied from 0.001 to ~0.3 cm<sup>2</sup>/(V∙s), with the largest being predicted for the crystal of the luminophore that consisted of a rigid donor and acceptor. We anticipate that the results obtained will be useful in the design of TADF luminophores for non-doped OLEDs, OLETs, and other organic light-emitting devices.https://www.mdpi.com/2073-4352/13/1/55OLEDcharge mobilityDFThopping transporttransfer integralsreorganization energy |
| spellingShingle | Andrey Y. Sosorev Dmitry I. Dominskiy Nikita O. Dubinets Charge Transport in Organic Semiconducting Crystals Exhibiting TADF: Insight from Quantum Chemical Calculations Crystals OLED charge mobility DFT hopping transport transfer integrals reorganization energy |
| title | Charge Transport in Organic Semiconducting Crystals Exhibiting TADF: Insight from Quantum Chemical Calculations |
| title_full | Charge Transport in Organic Semiconducting Crystals Exhibiting TADF: Insight from Quantum Chemical Calculations |
| title_fullStr | Charge Transport in Organic Semiconducting Crystals Exhibiting TADF: Insight from Quantum Chemical Calculations |
| title_full_unstemmed | Charge Transport in Organic Semiconducting Crystals Exhibiting TADF: Insight from Quantum Chemical Calculations |
| title_short | Charge Transport in Organic Semiconducting Crystals Exhibiting TADF: Insight from Quantum Chemical Calculations |
| title_sort | charge transport in organic semiconducting crystals exhibiting tadf insight from quantum chemical calculations |
| topic | OLED charge mobility DFT hopping transport transfer integrals reorganization energy |
| url | https://www.mdpi.com/2073-4352/13/1/55 |
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