g, 2.5 mol%) were placed in a sealed tube and then N-methylpyrrolidone (NMP) (1.00 ml)

Transcription

1 Supporting Information Molecular Design of Highly Efficient Thermally Activated Delayed Fluorescence Hosts for Blue Phosphorescent and Fluorescent Organic Light-Emitting Diodes Chih-Chun Lin,, Min-Jie Huang,, Ming-Jui Chiu, Man-Ping Huang, Ching-Chih Chang, Chuang-Yi Liao, Kai-Ming Chiang, Yu-Jeng Shiau, Tsu-Yu Chou, Li-Kang Chu, Hao- Wu Lin, and Chien-Hong Cheng*, Department of Chemistry, National Tsing Hua University, Hsinchu 33, Taiwan Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 33, Taiwan These authors contributed equally. Experimental details Synthesis -bromo-2-methyl-4-(phenylsulfonyl)benzene: 2-Bromo-5-iodotoluene (.4 ml, mmol), K 2 CO 3 (.5 g,. mmol), and CuI (.5 g, 2.5 mol%) were placed in a sealed tube and then N-methylpyrrolidone (NMP) (. ml) was added. The tube was then sealed with a septum and was evacuated and purged with nitrogen gas three times. Thiophenol (. ml,. mmol) was injected into the tube via a syringe. The septum was replaced by a cap and the sealed tube was heated in an oil bath at C for 2 h. After the reaction was completed and cooled to room temperature, the mixture was filtered through Celite pad and the resulting filtrate was extracted with ethyl acetate. The combined organic layer was dried by magnesium sulfate and concentrated under reduced pressure to give the crude product. This crude material was placed in a round-bottom flask and was dissolved in acetic acid ( ml). To the solution was added hydrogen peroxide solution (3 ml) dropwise and the mixture was then placed in 6 C oil bath for 2 h. After the reaction was completed and cooled to room temperature, the mixture was extracted with ethyl acetate. The combined organic layer was dried by magnesium sulfate and concentrated

2 under reduced pressure to give a crude mixture, which was purified by column chromatography to give white material in 85% yield. H NMR (4 MHz, CD 2 Cl 2, δ): (m, 2H), (m, H), 7.68 (d, J = 8.4 Hz, H), (m, 2H), (m, 2H), 2.44 (s, 3H); 3 C NMR ( MHz, CDCl 3, δ): 4.3, 4.6, 39.7, 33.3, 3.9, 29.4, 29.3, 27.6, 26.3, ,4,5,5-tetramethyl-2-(2-methyl-4-(phenylsulfonyl)phenyl)-,3,2-dioxaborolane -Bromo-2-methyl-4-(phenylsulfonyl)benzene (.3 g,. mmol), 4,4,4',4',5,5,5',5'- octamethyl-2,2'-bi(,3,2-dioxaborolane) (.34 g,.2 mmol), Pd(PPh 3 ) 2 Cl 2 (.35 g, 5 mol%), and potassium acetate (.29 g, 2.93 mmol) were placed in a sealed tube and dioxane (5 ml) was added to the tube. The sealed tube was evacuated and purged with nitrogen gas three times and then placed in 8 C oil bath for 2 h. After the reaction was completed, the reaction mixture was cooled to room temperature and filtered through a Celite pad. The filtrate was concentrated under reduced pressure to give the crude product, which was purified by column chromatography to give the desired white material in 45% yield. HNMR (4 MHz, CD 2 Cl 2, δ): (m, 2H), 7.84 (d, J = 8 Hz, H), (m, 2H), (m, H), (m, 2H), 2.56 (s, 3H),.32 (s, 2H); 3 C NMR ( MHz, CDCl 3, δ): 42.6, 42.9, 4.6, 36.5, 33., 29.2, 28., 27.6, 23.6, 84., 24.8,

3 9-(4-bromo-3-methylphenyl)-9H-carbazole or 9-(4-bromo-3-methylphenyl)-9H-carbazole-3- carbonitrile: 9H-Carbazole (.7 g,. mmol) or 9H-carbazole-3-carbonitrile (.9g,. mmol), K 2 CO 3 (.42 g, 3.6 mmol), and Cu (.2 g, 3.6 mmol) was placed in a sealed tube and DMF (4 ml) and 2-bromo-5-iodotoluene (.6mL,. mmol) were added to the tube. The sealed tube was evacuated and purged with nitrogen gas three times and was then heated in a 3 C oil bath with stirring for 48 h. After the reaction was completed and cooled to room temperature, the mixture was filtered through a Celite pad. The resulting filtrate was concentrated under reduced pressure to give the crude product. The crude material was purified by column chromatography to give desired product. 9-(4-bromo-3-methylphenyl)-9H-carbazole: White powder (7%). H NMR (4 MHz, CD 2 Cl 2, δ): 8.4 (dt, J = 8,.8 Hz, 2H), 7.77 (d, J = 8.4 Hz, H ), 7.47 (d, J = 2.4 Hz, H), (m, 4H), (m, 3H), 2.5 (s, 3H); 3 C NMR ( MHz, CDCl 3, δ): 4.6, 39.7, 36.8, 33.6, 29., 25.9, 25.8, 23.3, 23.3, 2.3, 2., 9.6, (4-bromo-3-methylphenyl)-9H-carbazole-3-carbonitrile: White powder (5%). H NMR (4 MHz, CD 2 Cl 2, δ): 8.47 (s, H ), 8.7 (d, J = 8. Hz, H ), 7.8 (d, J = 8.4 Hz, H), 7.76 (dd, J = 8.4,.6 Hz, H), (m, H), (m, 4H), 7.26 (dd, J = 8.4, 2.4 Hz, H), 2.5 (s, 3H); 3 C NMR ( MHz, CDCl 3, δ): 42.4, 4.4, 4.3, 35.5, 34., 29.2, 29.2, 27.5, 25.9, 25.3, 24.6, 23.5, 22.2, 2.4, 2.7, 2.3,.4,.2, 2.8,

4 Weight (%) exothermic a) b) BT- T d = 366 o C BT-2 T d = 395 o C Temperature ( o C) T g = 96 o C BT- BT Temperature ( o C) Figure S. (a) TGA and (b) DSC traces of BT- and BT-2 recorded under nitrogen at a heating rate of C/min. BT- BT-2 Hole Particle Figure S2. Natural transition orbitals of first triplet excited state for BT- and BT-2. 4

5 DF Intensity DF Intensity DF Intensity DF Intensity 2k 5k k 5k (a) BT- 276 mw/cm 2 37 mw/cm 2 4 mw/cm 2 84 mw/cm 2 74 mw/cm 2 65 mw/cm 2 46 mw/cm 2 2 mw/cm mw/cm mw/cm 2.4 mw/cm 2.9 mw/cm 2 3k 25k 2k 5k k 5k (b) BT mw/cm mw/cm 2 42 mw/cm 2 89 mw/cm 2 66 mw/cm 2 37 mw/cm 2 9 mw/cm 2 2 mw/cm mw/cm mw/cm 2. mw/cm Wavelength (nm) Wavelength (nm) 2k 9k 6k (c) BT- 3 K 275 K 25 K 225 K 2 K 75 K 5 K 25 K K 77 K 2k 9k 6k (d) BT-2 3 K 275 K 25 K 225 K 2 K 75 K 5 K 25 K K 77 K 3k 3k Wavelength (nm) Wavelength (nm) Figure S3. (a, b) Power and (c, d) temperature dependent DF spectra of BT- and BT-2 in the thin film. The DF spectra were measured on Edinburgh spectrometer combined with gated photomultiplier module. The gate delay after excitation was set at s, and the gate width for data collection was 2 s. 5

6 a) HOMO = 5.88 ev b) HOMO = 6. ev Figure S4. HOMO levels of (a) BT- and (b) BT-2 acquired from photoelectron spectrometer (AC-II). 6

7 Intensity (a.u) Current Density (ma/cm 2 ) Current Density (ma/cm 2 ) E3 (a) E2 E E E- BT- HOD BT- EOD E Voltage (V) E3 (b) E2 E E E- BT-2 HOD BT-2 EOD E Voltage (V) Figure S5. Current density-voltage characteristics of the hole-only and electron-only devices for (a) BT- and (b) BT CzPN - UV FIrpic - UV BT- - thin film BT-2 - thin film wavelength (nm) Figure S6. The photoluminescence spectra of BT films and the UV-Vis absorption of the dopants in toluene. 7

8 Power efficiency (lm/w) Power efficiency (lm/w) Current density (ma/cm 2 ) Luminance (cd/m 2 ) Current density (ma/cm 2 ) Luminance (cd/m 2 ) 5 4 (a) BT- (device A) BT-2 (device B) E5 E4 5 4 (b) BT- (device C) BT-2 (device D) E4 3 E3 3 E3 2 E2 2 E2 E E Voltage (V) Voltage (V) (c) (d) BT- (device A) BT-2 (device B) BT- (device C) BT-2 (device D). Luminance (cd/m 2 ). Luminance (cd/m 2 ) Figure S7. Current-density-voltage-luminance and power efficiency-luminance characteristics of (a,c) FIrpic- and (b,d) 2CzPN-based devices hosted by BT- and BT Lambertian Device A Device B Lambertian Device C Device D Figure S8. Angle-dependent emission patterns of Devices A-D. The solid line represents the Lambertian distribution. 8

9 Intensity (a.u.) E- BT- BT-2 E-2 E-3 E Time ( s) Figure S9. Transient PL decay curves of 2CzPN-doped BT films. Analysis of the excited state dynamics for 2CzPN doped in the BTs film For TADF emitter, the relationship between quantum yields and lifetimes of prompt and delayed components can be described by the following equations: F k s r k s kr s nr k ISC k k s r F k k TADF ( ISC RISC ) F k ISC k s r k k ISC s nr k ISC k k ISC F s r F ISC k ISC ISC RISC F RISC kfktadf TADF krisc kisc F where k s r and k s nr represent, respectively, the radiative and non-radiative decay rate constants of the first singlet excited state, k ISC and k RISC denote the ISC and RISC rate constants, respectively, and k F and k TADF (=/ TADF ) are the rate constants of the prompt and delayed components, respectively. The prompt ( F ) and delayed ( TADF ) lifetimes were acquired from the fitting of the transient PL decay curve, while the prompt ( F ) and delayed ( TADF ) quantum yields were determined from the ratio between prompt and delayed components. Assuming that the k nr s is zero at room temperature, the values of k r s, k ISC, and k RISC can be calculated from above-mentioned equations and are summarized in Table S. F 9

10 E.Q.E (%) E.Q.E (%) E.Q.E (%) E.Q.E (%) Table S. Photophysical data of 2CzPN doped into BT films ( wt%) at room temperature F TADF F TADF k F k TADF k RISC (%) (%) (%) (ns) ( s) ( s) ( s) ( s) ( s) k r s (a) (b) BT- (device A) TTA simulation BT-2 (device B) TTA simulation.. Current Density (ma/cm 2 ) (c).. Current Density (ma/cm 2 ) (d) BT- (device C) TTA simulation BT-2 (device D) TTA simulation.. Current Density (ma/cm 2 ).. Current Density (ma/cm 2 ) Figure S. External quantum efficiency (E.Q.E.) as a function of current density for (a,b) FIrpic- and (c,d) 2CzPN-based devices using BT- and BT-2 as the host. The solid lines are simulated results for the corresponding curves by TTA model. The fitted J values of devices A-D are 9, 6, 2.2, and.4 ma/cm 2, respectively.

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