Year

2019

Type(s)

Journal Article

Author(s)

Nobuyasu, R.S. and Ward, J.S. and Gibson, J. and Laidlaw, B.A. and Ren, Z. and Data, P. and Batsanov, A.S. and Penfold, T.J. and Bryce, M.R. and Dias, F.B.

Source

Journal of Materials Chemistry C, 7(22): 6672—6684, 2019

Url

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066926605&doi=10.1039%2fc9tc00720b&partnerID=40&md5=a86f2b321881d57a58182f6e7fee865e

BibTeX

BibTeX

BibTeX

@ARTICLE{Nobuyasu20196672, author={Nobuyasu, R.S. and Ward, J.S. and Gibson, J. and Laidlaw, B.A. and Ren, Z. and Data, P. and Batsanov, A.S. and Penfold, T.J. and Bryce, M.R. and Dias, F.B.}, title={The influence of molecular geometry on the efficiency of thermally activated delayed fluorescence}, journal={Journal of Materials Chemistry C}, year={2019}, volume={7}, number={22}, pages={6672-6684}, doi={10.1039/c9tc00720b}, note={cited By 9}, url={https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066926605&doi=10.1039%2fc9tc00720b&partnerID=40&md5=a86f2b321881d57a58182f6e7fee865e}, affiliation={Durham University, Physics Department, South Road, Durham, DH1 3LE, United Kingdom; Durham University, Chemistry Department, South Road, Durham, DH1 3LE, United Kingdom; Chemistry-School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom; Beijing University of Chemical Technology, State Key Laboratory of Chemical Resource Engineering, Beijing, 100029, China; Faculty of Chemistry, Silesian University of Technology, M. Strzody 9, Gliwice, 44-100, Poland}, abstract={In this work we successfully developed a strategy for positively influencing the conformation of thermally activated delayed fluorescence (TADF) molecules containing phenothiazine as the electron donor (D) unit, and dibenzothiophene-S,S-dioxide as the acceptor (A), linked in D-A and D-A-D structures. In this strategy the effect of restricted molecular geometry is explored to maximize TADF emission. The presence of bulky substituents in different positions on the donor unit forces the molecules to adopt an axial conformer where the singlet charge transfer state is shifted to higher energy, resulting in the oscillator strength and luminescence efficiency decreasing. With bulky substituents on the acceptor unit, the molecules adopt an equatorial geometry, where the donor and acceptor units are locked in relative near-orthogonal geometry. In this case the individual signatures of the donor and acceptor units are evident in the absorption spectra, demonstrating that the substituent in the acceptor uncouples the electronic linkage between the donor and acceptor more effectively than with donor substitution. In contrast with the axial conformers that show very weak TADF, even with a small singlet triplet gap, molecules with equatorial geometry show stronger oscillator strength and luminescence efficiency and are excellent TADF emitters. Acceptor-substituted molecules 6 and 7 in particular show extremely high TADF efficiency in solution and solid film, even with a singlet-triplet energy gap around 0.2 eV. This extensive study provides important criteria for the design of novel TADF and room temperature phosphorescence (RTP) emitters with optimized geometry. © 2019 The Royal Society of Chemistry.}, keywords={Charge transfer; Energy efficiency; Fluorescence; Molecular structure; Molecules, Charge transfer state; Luminescence efficiencies; Molecular geometries; Optimized geometries; Oscillator strengths; Room temperature phosphorescence; Singlet-triplet energy gap; Thermally activated delayed fluorescences, Geometry}, funding_details={Horizon 2020Horizon 2020, EP/R021503/1, EP/P012388/1, 732103, EP/N028511/1}, funding_details={European CommissionEuropean Commission, EC}, funding_details={Engineering and Physical Sciences Research CouncilEngineering and Physical Sciences Research Council, EPSRC, EP/L02621X/1}, funding_details={China Scholarship CouncilChina Scholarship Council, CSC}, funding_details={Horizon 2020Horizon 2020, 778158}, funding_details={Fundacja na rzecz Nauki PolskiejFundacja na rzecz Nauki Polskiej, FNP}, funding_details={European Regional Development FundEuropean Regional Development Fund, FEDER}, funding_text 1={R. S. N. thanks the financial support from CAPES Foundation, Ministry of Education-Brazil (Grant No. BEX9474-13-7). Z. R. thanks the China Scholarship Council for funding a visit to Durham University. P. D. kindly acknowledges the support received from the First Team program of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund, project no. First TEAM 2017-4/32. F. B. D. and P. D. acknowledge supporting actions by the EU’s Horizon 2020 OCTA project under grant agreement no. 778158. F. B. D. thanks also EPSRC for funding Grant EP/L02621X/1. J. S. W. and M. R. B. thank EU Horizon 2020 Grant Agreement No. 732103 (HyperOLED) for funding. T. J. P. thanks the EPSRC for funding Grants EP/N028511/1, EP/R021503/1 and EP/P012388/1. The Diamond Light Source is thanked for the award of instrument time on Station I19 (MT 11145), and the instrument scientists are thanked for their kind support.}, references={Reineke, S., Seidler, N., Yost, S.R., Prins, F., Tisdale, W.A., Baldo, M.A., (2013) Appl. Phys. Lett., 103, p. 093302; Kraus, H., Bange, S., Frunder, F., Scherf, U., Boehme, C., Lupton, J.M., (2017) Phys. Rev. B, 95, p. 241201; Köhler, A., Bässler, H., (2009) Mater. Sci. Eng., R, 66, pp. 71-109; Burroughes, J.H., Bradley, D.D.C., Brown, A.R., Marks, R.N., Mackay, K., Friend, R.H., Burn, P.L., Holmes, A.B., (1990) Nature, 347, pp. 539-541; Tang, C.W., Vanslyke, S.A., (1987) Appl. Phys. Lett., 51, pp. 913-915; Forrest, S.R., Baldo, M.A., O'Brien, D.F., You, Y., Shoustikov, A., Sibley, S., Thompson, M.E., (1998) Nature, 395, pp. 151-154; Adachi, C., Baldo, M.A., Thompson, M.E., Forrest, S.R., (2001) J. Appl. Phys., 90, pp. 5048-5051; Yang, X., Zhou, G., Wong, W.Y., (2015) Chem. Soc. Rev., 44, pp. 8484-8575; Zysman-Colman, E., (2017) Iridium(III) in Optoelectronic and Photonics Applications, , John Wiley & Sons; Sivasubramaniam, V., Brodkorb, F., Hanning, S., Loebl, H.P., Van Elsbergen, V., Boerner, H., Scherf, U., Kreyenschmidt, M., (2009) J. Fluorine Chem., 130, pp. 640-649; Schmidbauer, S., Hohenleutner, A., Konig, B., (2013) Adv. Mater., 25, pp. 2114-2129; Uoyama, H., Goushi, K., Shizu, K., Nomura, H., Adachi, C., (2012) Nature, 492, pp. 234-238; Dias, F.B., Bourdakos, K.N., Jankus, V., Moss, K.C., Kamtekar, K.T., Bhalla, V., Santos, J., Monkman, A.P., (2013) Adv. Mater., 25, pp. 3707-3714; Dos Santos, P.L., Ward, J.S., Bryce, M.R., Monkman, A.P., (2016) J. Phys. Chem. Lett., 7, pp. 3341-3346; Dias, F.B., Penfold, T.J., Monkman, A.P., (2017) Methods Appl. Fluoresc., 5, p. 012001; Dos Santos, P.L., Ward, J.S., Congrave, D.G., Batsanov, A.S., Eng, J., Stacey, J.E., Penfold, T.J., Bryce, M.R., (2018) Adv. Sci., 5, p. 1700989; Kim, K.J., Kim, G.H., Lampande, R., Ahn, D.H., Im, J.B., Moon, J.S., Lee, J.K., Kwon, J.H., (2018) J. Mater. Chem. C, 6, pp. 1343-1348; Wu, T.L., Huang, M.J., Lin, C.C., Huang, P.Y., Chou, T.Y., Chen-Cheng, R.W., Lin, H.W., Cheng, C.H., (2018) Nat. Photonics, 12, pp. 235-240; Tao, Y., Yuan, K., Chen, T., Xu, P., Li, H., Chen, R., Zheng, C., Huang, W., (2014) Adv. Mater., 26, pp. 7931-7958; Sandanayaka, A.S.D., Yoshida, K., Matsushima, T., Adachi, C., (2015) J. Phys. Chem. C, 119, pp. 7631-7636; Sandanayaka, A.S.D., Matsushima, T., Adachi, C., (2015) J. Phys. Chem. C, 119, pp. 23845-23851; Zhang, Q., Kuwabara, H., Potscavage, W.J., Huang, S., Hatae, Y., Shibata, T., Adachi, C., (2014) J. Am. Chem. Soc., 136, pp. 18070-18081; Wong, M.Y., Zysman-Colman, E., (2017) Adv. Mater., 29, p. 1605444; Liu, Y., Li, C., Ren, Z., Yan, S., Bryce, M.R., (2018) Nat. Rev. Mater., 3, p. 18020; Etherington, M.K., Franchello, F., Gibson, J., Northey, T., Santos, J., Ward, J.S., Higginbotham, H.F., Monkman, A.P., (2017) Nat. Commun., 8, p. 14987; Dias, F.B., Santos, J., Graves, D.R., Data, P., Nobuyasu, R.S., Fox, M.A., Batsanov, A.S., Monkman, A.P., (2016) Adv. Sci., 3, p. 1600080; Northey, T., Stacey, J., Penfold, T.J., (2017) J. Mater. Chem. C, 5, pp. 11001-11009; Penfold, T.J., Gindensperger, E., Daniel, C., Marian, C.M., (2018) Chem. Rev., 118, pp. 6975-7025; Penfold, T.J., Dias, F.B., Monkman, A.P., (2018) Chem. Commun., 54, pp. 3926-3935; Gibson, J., Monkman, A.P., Penfold, T.J., (2016) ChemPhysChem, 17, pp. 2956-2961; Gibson, J., Penfold, T.J., (2017) Phys. Chem. Chem. Phys., 19, pp. 8428-8434; Ward, J.S., Nobuyasu, R.S., Batsanov, A.S., Data, P., Monkman, A.P., Dias, F.B., Bryce, M.R., (2016) Chem. Commun., 52, pp. 2612-2615; Nobuyasu, R.S., Ren, Z., Griffiths, G.C., Batsanov, A.S., Data, P., Yan, S., Monkman, A.P., Dias, F.B., (2016) Adv. Opt. Mater., 4, pp. 597-607; Stockmann, A., Kurzawa, J., Fritz, N., Acar, N., Schneider, S., Daub, J., Engl, R., Clark, T., (2002) J. Phys. Chem. A, 106, pp. 7958-7970; Ward, J.S., Nobuyasu, R.S., Fox, M.A., Batsanov, A.S., Santos, J., Dias, F.B., Bryce, M.R., (2018) J. Org. Chem., 83, pp. 14431-14442; Huang, R., Ward, J.S., Kukhta, N.A., Avó, J., Gibson, J., Penfold, T., Lima, J.C., Dias, F.B., (2018) J. Mater. Chem. C, 6, pp. 9238-9247}, correspondence_address1={Penfold, T.J.; Chemistry-School of Natural and Environmental Sciences, Newcastle UniversityUnited Kingdom}, publisher={Royal Society of Chemistry}, issn={20507534}, coden={JMCCC}, language={English}, abbrev_source_title={J. Mater. Chem. C}, document_type={Article}, source={Scopus},