SUPPORTIG IFORMATIO [1,2,4]Triazolo[1,5-a]pyridine-based Host Materials for Green Phosphorescent and Delayed-Fluorescence OLEDs with Low Efficiency Roll-off Wenxuan Song, a Yi Chen, a Qihao Xu, a Haichuan Mu, b Jingjing Cao, *c Jinhai Huang* d and Jianhua Su* a a Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science & Technology, Shanghai 200237, PR China. E-mail: bbsjh@ecust.edu.cn b Department of Physics, School of Science, East China University of Science and Technology, Shanghai 200237, PR China. c State Key Laboratory of Applied Organic Chemistry (SKLAOC); College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China. Email: caojj@lzu.edu.cn d Shanghai Taoe Chemical Technology Co., Ltd, Shanghai, PR China. E-mail: dele12@163.com S-1
CATALOGUE General information... S-3 Device fabrication and performance measurements... S-4 Synthesis and characterization... S-5 Optophysical properties... S-9 Device performance... S-10 References... S-16 S-2
General information All the reagents and materials were purchased from Energy Chemical and TCI (Shanghai) Development Co., Ltd. without further purification. The 1 H MR and 13 C MR spectra were recorded on a Brucker AM 400 spectrometer with tetramethylsilane as an internal reference. Molecular masses were determined by a Waters LCT premier XE spectrometer. The UV-Vis absorption spectra were recorded on a Varian Cary 500 spectrophotometer while PL spectra were recorded on room temperature by Varian-Cary fluorescence spectrophotometer. The cyclic voltammetry experiments were performed by a CH Instruments Model 1200B electrochemical work station using a conventional three-electrode configuration with a glassy carbon working electrode, a Pt wire counter electrode, and a regular calomel reference electrode in saturated KCl solution. The oxidation potential was measured in dichloromethane solution containing of 0.1 M tetra-nbutylammonium hexafluorophosphate (TBAPF6) as the supporting electrolyte at a scan rate of 0.1 V/s. The differential scanning calorimetry (DSC) analysis was performed on a ETZSCH STA 449F3 simultaneous thermogravimetric analyzer with a heating scan rate of 10 /min from 0 to 250 under nitrogen atmosphere. Thermogravimetric analysis (TGA) was carried out on the TGA instrument by measuring weight loss of samples with a heating scan rate of 10 /min from 50 to 800 under nitrogen. S-3
Device fabrication and performance measurements Indium tin oxide (ITO)-coated glass substrates were cleaned with acetone, detergent, acetone, isopropanol and deionized water. The substrates should be dry under nitrogen and were then subjected to UV ozone treatment for 15 min to improve the work function of ITO. PEDOT:PSS was spin-coated onto the ITO substrate at a speed of 3000 rpm for 1 min and annealed at 120 ºC for 10 min before they were loaded into a vacuum evaporation system. The organic compounds were deposition in a high vacuum (~10-4 Pa) at the rate of 1 2 Å s 1. Then a cathode composed of LiF and Al metal was deposited sequentially onto the substrate. The performance parameters, including EL spectra, CIE coordinates, and J V B curves of the devices, were measured using a program-controlled Konica Minolta CS-2000 photometer and a source-measure-unit Keithley 2400 under ambient conditions at room temperature. S-4
Synthesis and characterization Figure S1. The 1 H MR and 13 C MR of TP26Cz1 S-5
Figure S2. The 1 H MR and 13 C MR of TP26Cz2 S-6
Figure S3. The 1 H MR and 13 C MR of TP27Cz1 S-7
Figure S4. The 1 H MR and 13 C MR of TP27Cz2 S-8
Optophysical properties Figure S5. Solvatochromism of (a) TP26Cz1, (b) TP26Cz2, (c) TP27Cz1 and (d) TP27Cz2 in various solvents. Figure S6. Lippert Mataga plots of TP26Cz1, TP26Cz2, TP27Cz1 and TP27Cz2 S-9
Device performance O O SO 3(H) Ir S n Pedot:PSS n 3 Ir(ppy) 3 TAPC C C TCTA 4CzIP TmPyPB Figure S7. The energy diagram and the molecular structures used in PhOLEDs devices S-10
Device TAPC(nm) TmPyPB(nm) V on (V) η c max (cd A -1 ) η p max (lm W -1 ) η ext max (%) G11 35 45 4.1 76.3 43.6 22.3 G12 35 55 4.1 75.0 44.5 21.7 G13 45 45 4.1 77.4 47.3 22.4 G14 45 55 4.1 77.8 44.4 22.8 Figure S8. Performances of TP26Cz1 hosted green PhOLEDs device with different thickness of HTL and ETL Device TAPC(nm) TmPyPB(nm) V on (V) η c max (cd A -1 ) η p max (lm W -1 ) η ext max (%) G21 35 45 3.1 78.9 58.6 23.1 G22 35 55 3.1 82.0 64.6 24.1 G23 45 45 3.0 83.0 67.0 24.3 G24 45 55 3.1 92.1 70.0 25.9 Figure S9. Performances of TP26Cz2 hosted green PhOLEDs device with different thickness of HTL and ETL S-11
Figure S10. EL spectra of devices P1 (a), P2 (b), P3 (c) and P4 (d) at different voltages. Figure S11. EL Spectra of devices F1 (a), F2 (b), F3 (c) and F4 (d) at different voltages. S-12
Host η c (cd A -1 ) η ext (%) @ max @1000cd/m 2 @5000cd/m 2 @ max @1000cd/m 2 @5000cd/m 2 TP26Cz1 77.8, 77.9, 75.2, 77.1, 77.1,74.2 72.7, 74.3, 71.3 22.8, 21.7, 22.6 22.7, 22.5, 21.7 21.5, 21.2, 20.8 TP26Cz2 92.1, 91.1, 87.2 89.7, 89.0, 83.1 91.4, 86.8, 82.5 24.3, 25.9, 26.6 26.2, 25.1, 24.1 25.7, 25.4, 24.4 TP27Cz1 79.1, 78.7, 76.1 77.2, 76.7, 71.7 77.9, 77.9, 73.6 22.6, 22.6, 22.0 22.1, 22.1, 21.1 22.4, 22.2, 21.5 TP27Cz2 91.1, 89.8, 87.3 89.9, 88.7, 87.5 87.0, 86.0, 85.7 25.6, 25.3, 25.5 25.2, 24.9, 24.5 25.4, 25.2, 25.0 Figure S12. The electroluminescence efficiencies of the devices P1 (a), P2 (b), P3 (c) and P4 (d). (three times datas) S-13
Host η c (cd A -1 ) η ext (%) @ max @1000cd/m 2 @5000cd/m 2 @ max @1000cd/m 2 @5000cd/m 2 TP26Cz1 53.9, 51.6 52.4, 50.9 40.7, 39.0 15.7, 15.2 15.6, 15.1 12.2, 11.6 TP26Cz2 48.9, 50.5 46.9, 45.4 38.4, 37.0 15.4, 15.2 13.9, 13.6 11.4, 11.1 TP27Cz1 49.8, 46.9 45.6, 42.3 28.2, 26.3 14.5, 13.8 13.4, 12.6 8.2, 7.6 TP27Cz2 51.4, 52.9 43.4, 41.6 23.7, 22.6 14.9, 15.5 12.6, 12.2 7.0, 6.4 Figure S13. The electroluminescence efficiencies of the devices F1 (a), F2 (b), F3 (c) and F4 (d). (two times datas) S-14
Table S1. The efficiencies and efficiency roll-off of previous reported devices based on Ir(ppy) 3 and reported hosts. Hosts η ext (%) Refs @ max @1000cd/m 2 @5000cd/m 2 @10000cd/m 2 TP26Cz2 25.6 25.1 25.2 24.2% This work TP27Cz2 25.4 24.9 24.2 23.1% This work BTP2 24.7 24.1 23%* Ref 1 PBICT 23.9 22.5% Ref 2 3C44BCz 30.4 24.4 15%* Ref 3 p-pypomcp 28.2 22.7 Ref 4 o-czthz 26.1 23.7 21%* 20.3% Ref 5 DCzDC 23.8 23.7 21%* Ref 6 *Obtained by reading from the figures of the device performances S-15
References (1) Lee, C. W.; Lee, J. Y., Benzo[4,5]thieno[2,3-b]pyridine Derivatives as Host Materials for High Efficiency Green and Blue Phosphorescent Organic Light-emitting Diodes. Chem. Commun. 2013, 49, 1446-1448. (2) Zhang, D.; Duan, L.; Zhang, D.; Qiu, Y., Towards Ideal Electrophosphorescent Devices with Low Dopant Concentrations: the Key Role of Triplet Up-conversion. J. Mater. Chem. C 2014, 2, 8983-8989. (3) Kim, M.; Lee, J. Y., Engineering of Interconnect Position of Bicarbazole for High External Quantum Efficiency in Green and Blue Phosphorescent Organic Light-emitting Diodes. ACS Appl. Mater. Interfaces 2014, 6, 14874-14880. (4) Li, W.; Li, J.; Liu, D.; Li, D.; Zhang, D., Dual n-type Units Including Pyridine and Diphenylphosphine Oxide: Effective Design Strategy of Host Materials for High-performance Organic Light-emitting Diodes. Chem. Sci. 2016, 7, 6706-6714. (5) Jin, J.; Zhang, W.; Wang, B.; Mu, G.; Xu, P.; Wang, L.; Huang, H.; Chen, J.; Ma, D., Construction of High Tg Bipolar Host Materials with Balanced Electron Hole Mobility Based on 1,2,4-Thiadiazole for Phosphorescent Organic Light-Emitting Diodes. Chem. Mater. 2014, 26, 2388-2395. (6) Cho, Y. J.; Yook, K. S.; Lee, J. Y., A Universal Host Material for High External Quantum Efficiency Close to 25% and Long Lifetime in Green Fluorescent and Phosphorescent OLEDs. Adv. Mater. 2014, 26, 4050-4055. S-16