Electronic Supplementary Material (ESI) for Journal of Materials Chemistry C. This journal is The Royal Society of Chemistry 2018 Electronic Supplementary Information Room temperature phosphorescence vs thermally activated delayed fluorescence in carbazole pyrimidine cored compounds Tomas Serevičius a*, Tadas Bučiūnas a, Jonas Bucevičius b, Jelena Dodonova b, Sigitas Tumkevičius b, Karolis Kazlauskas a and Saulius Juršėnas a [a] Institute of Photonics and Nanotechnology, Faculty of Physics, Vilnius University, Sauletekio 3, LT-10257 Vilnius, Lithuania [b] Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Sauletekio 3, LT-10257, LT-03225 Vilnius, Lithuania * corresponding author: tomas.serevicius@tmi.vu.lt
Table S1 Peak positions of absorption, fluorescence and phosphorescence spectra of the compounds 1a-d in 1 w.t.% Zeonex and PMMA thin films. ABS Zeonex (nm) [a] PMMA ABS (nm) [b] Zeonex FL (nm) [c] PMMA FL (nm) [d] Zeonex PH (nm) [e] PMMA PH (nm) [f] 1a 352 342 384 404 460 461 1b 355 342 388 404 463 463 1c 362 362 394 420 475 460 1d 358 344 435 475 477 488 [a], [c], [e] Absorption, fluorescence and phosphorescence spectrum maximum, respectively, in 1 w.t. % Zeonex film. [b], [d], [f] Absorption, fluorescence and phosphorescence spectrum maximum, respectively, in 1 w.t. %PMMA film. Table S2 Orbital composition of S 0 T 1 and S 0 T 2 transitions with fractional contribution values for carbazole-pyrimidine compounds 1a-1d. The main transitions are indicated in bold. S 0 T 1 S 0 T 2 1a 1b 1c 1d Transition Contribution (%) Transition Contribution (%) HOMO-5 LUMO HOMO-3 LUMO+1 +1 HOMO-11 LUMO HOMO-10 LUMO+1 LUMO-10 LUMO+4 HOMO-5 LUMO+1 +1 +5 HOMO-8 LUMO HOMO-7 LUMO HOMO-5 LUMO+1 +1 +1 HOMO-10 LUMO HOMO-7 LUMO+1 HOMO-2 LUMO +1 +5 +7 0.13 2 7 0.61 0.12 0.11 0.19 0.46 0.13 0.69 9 2 0.77 +1 HOMO-3 LUMO +1 HOMO-10 LUMO HOMO-5 LUMO +1 +4 HOMO-7 LUMO HOMO-5 LUMO +1 +1 HOMO-7 LUMO 2 0.10 0.75 7 0.76 6 0.77 0.95
Normalized emiss. int. (arb. un.) Phosphorescence @77K Phosphorescence @RT (Spectra in He - spectra in air) 1a Zeonex 450 500 550 1b Zeonex 1a PMMA 1b PMMA 450 500 550 Emission intensity (arb. un.) Fig. S1 Phosphorescence spectra of compounds 1a and 1b in 1w.t. % in Zeonex and PMMA films at 77K (red lines) and room temperature (black lines). Room temperature PH spectra were obtained by subtracting the Fl spectra obtained in oxygen-saturated ambient from those obtained in oxygendeficient ambient. Heat flow (mw) 3 2 1 T g Zeonex ~ 135 o C T g PMMA ~ 105 o C Zeonex PMMA 50 75 100 125 150 175 200 225 250 Temperature ( o C) Fig. S2 Differential scanning calorimetry curves of Zeonex and PMMA.
Intensity (arb. un.) 0.8 0.6 0.4 0.2 1d 3 w.t.% in DPEPO He F = 0.35 Air F = 0.19 Air F Norm. Intensity 475 nm 490 nm PMMA DPEPO Fig. S3 Fluorescence spectra of 3 w.t.% DPEPO film of compound 1d in oxygen-saturated (black line) and oxygen-deficient (red line) ambient. Φ F is a fluorescence quantum yield, Φ F * - fluorescence quantum yield excluding the TADF part (true Φ F for the prompt fluorescence). Inset shows fluorescence spectra of 3 w.t.% DPEPO (black line) and 1 w.t.% PMMA (red line) films of compound 1d. Intensity (arb. un.) 10 14 10 13 10 12 10 11 10 10 10 9 10 8 10 7 1d 3% wt. DPEPO film PR =9.89 ns He Air DF / PF = 4,47 DF / PF = 11,41 Intensity (arb. un.) DF =90 s 10 6 10-9 10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 10-3 10-5 Time (s) 10-1 1d 1% w.t. PMMA 3% w.t. DPEPO 10-7 1E-9 1E-7 1E-5 1E-3 0.1 Time (s) Fig. S4 Log log scale photoluminescence decays of 3 w.t.% DPEPO film of compoud 1d in oxygen-saturated and oxygen-deficient ambients. The inset shows the comparison of log log scale photoluminescence decays of 1d in 1w.t.% PMMA film (red triangles) and 3 w.t.% DPEPO film (open squares). Blue line is the bi-exponential fit.
Fl intensity (arb. un.) 10 11 10 10 10 9 10 8 10 7 10 6 10 5 a) Prompt FL 1d in 1w.t.% PMMA Temperature/K 10 50 100 200 250 TADF 270 300 330 10-9 10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 Time (s) FL intensity (arb. un.) 10 8 10 7 I DF ~I ex 1 b) 10 6 10 1 10 2 10 3 10 4 Pulse energy (nj) Fig. S5 a) Log log scale photoluminescence decays of compound 1d in 1% w.t. PMMA at various temperatures. The emergency of TADF is clearly seen at the temperatures above ~200K. b) Delayed fluorescence intensity dependence on the laser fluence of compound 1d in 1% w.t. PMMA. Red line shows linear fit. Normalized fl intensity (arb. un) 10 2 10 1 Dipole moment of host molecules 10 0 10-1 10-2 10-3 10-4 10-5 10-6 10-7 1d in Zeonex, 1 w.t.% PMMA, 1 w.t.% DPEPO, 3 w.t.% 10-9 10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 Time (ns) Fig. S6 Fluorescence decay transients of compound 1d in diluted Zeonex (black figures), PMMA (red figures) and DPEPO (blue figures) films. Transients were normalized to initial intensity of delayed fluorescence. Clear trend of decrease of delayed fluorescence lifetime (τ TADF ) upon the increase of dipole moment of host molecules is observed. TADF
Nor. fl int. (arb. un.) 1d in 3 w.t. % in DPEPO In air Delay time 1.25 ns 12 ns 160 ns 2 ms 3 ms Nor. fl int. (arb. un.) In He 3.18 ev 3.02 ev Delay time 1.25 ns Fig. S7 Normalized time resolved fluorescence spectra of 3 w.t.% 1d:DPEPO film in oxygensaturated (upper picture) and oxygen-deficient (lower picture) ambients. Numbers denotes the delay time. Numbers near the arrows denotes the on-set energies of fluorescence spectra. All spectra were shifted vertically for clarity. Norm. fl intensity (arb. un.) In He ambient 3 LE 12 ns 160 ns 2 ms 77 ms 1c in PMMA 0 ns 12 ns 160 ns Fig. S8 Normalized time resolved fluorescence spectra of 1 w.t.% 1c PMMA film in oxygendeficient ambient. Numbers denote the delay time. Dotted spectrum is phosphorescence spectra obtained at 77K temperature. All spectra were shifted vertically for clarity. 2 ms 77 ms
Norm. fl intensity (arb. un.) Shift - 200 mev 1d in 1 wt% Zeonex Delay time 1.25 ns Fig. S9 Normalized time resolved fluorescence spectra of 1 w.t.% 1d Zeonex film in oxygendeficient ambient. Numbers denotes the delay time. Dark grey spectrum is phosphorescence spectra obtained at 77K temperature. All spectra were shifted vertically for clarity. 3 LE 20 ns 50 s 1 ms 89 ms