# Highly Efficient Blue Host Compound Based on an Anthracene Moiety for OLEDs
## 2 Materials and Methods  
### General Information and Device Fabrication  
Reactants and solvents were acquired as reagent grade and utilized without any further purification. Analytical thin-layer chromatography (TLC) was conducted on Merck 60 F254 silica gel plates, while column chromatography was carried out using Merck 60 silica gel (230-400 mesh). Proton nuclear magnetic resonance (\({}^{1}\)H-NMR) spectra were recorded on Bruker Advance 300 spectrometers (Bruker, Billerica, MA, USA). Fast atom bombardment positive-ion mass spectrometry (FAB+-MS) was conducted on a JMS-600W or JMS-700 spectrometer, as well as a 6890 Series instrument. The optical UV-Vis absorption spectra were obtained using a Lambda 1050 UV/Vis/NIR spectrometer (Perkin Elmer, Waltham, MA, USA). A Perkin-Elmer luminescence spectrometer LS55 (Xenon flash tube) was used to perform PL spectroscopy. Under a nitrogen atmosphere, the glass transition temperatures (T\({}_{g}\)) and melting temperatures (T\({}_{m}\)) of the compounds were determined using a differential scanning calorimeter (DSC) Discovery DSC25 (TA Instruments, Lukens Dr, New Castle, DE, USA). The sample mass used was 4.5 mg. The compounds were subjected to heating to 350 \({}^{\circ}\)C at a rate of 5 \({}^{\circ}\)C/min and cooled at the same rate. Thermal gravimetric analysis (TGA) was conducted with a TGA4000 (Perkin Elmer) to measure degradation temperatures (T\({}_{d}\)), heating samples to 700 \({}^{\circ}\)C at a rate of 10 \({}^{\circ}\)C/min. The HOMO energy levels were determined with ultraviolet photoelectron spectroscopy (Riken Keiki AC-2, Tokyo, Japan). The lowest unoccupied molecular orbital (LUMO) energy levels were derived from the highest occupied molecular orbital (HOMO) energy levels and the band gaps. The HOMO energy level was determined with cyclic voltammetry (CV) by using EQCM (Wizmac, Daejeon, Republic of Korea). Electrolyte was prepared in 0.1 M solution using TBAPF\({}_{6}\) and dichloromethane, Ag/AgCl was used as reference electrode, glassy carbon was the working electrode, and platinum comprised the counter electrode. For the vacuum-deposited film, the organic layer was deposited onto a glass substrate at a pressure of 10\({}^{-6}\) torr, with a deposition rate of 1 A/s, resulting in a film thickness of 500 A. The film thickness was obtained using an Alpha step stylus profiler (KLA Tencor (D-500). For the EL devices, all organic layers were deposited under 10\({}^{-6}\) torr, with a rate of deposition of 1 A/s to give a deposition area of 4 mm\({}^{2}\). A non-doped OLED device emitting blue light was constructed with the following layered structure: ITO/4,4\({}^{\prime}\)A\({}^{\prime\prime}\)-tris(N-(2-naphthyl)-N-phenylamino)-triphenylamine (2-TNATA) (60 nm)/(N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine) (NPB) (15 nm)/emitting layer (EML) (35 nm)/tris(8-hydroxyquinolinato) aluminium (Alq3) (20 nm)/LiF (1 nm)/Al (200 nm). In this configuration, 2-TNATA acts as the hole injection layer (HIL), NPB serves as the hole transporting layer (HTL), Alq\({}_{3}\) functions as the electron transporting layer (ETL), LiF serves as the electron injection layer (EIL), ITO acts as the anode, and Al serves as the cathode. The doped device was composed of ITO (150 nm)/dipyrazino[2,3-f2\({}^{\prime}\),3-l]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN) (10 nm)/N-([1,1\({}^{\prime}\)-biphenyl]-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)spiro[benzo[de]anthracene-7,9\({}^{\prime}\)-fluoren]-2\({}^{\prime}\)-amine (MHT210) (100 nm)/N-([1,1\({}^{\prime}\)-biphenyl]-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)spiro[benzo[de]anthracene-7,9\({}^{\prime}\)-fluoren]-4\({}^{\prime}\)-amine (MEB310) (10 nm)/2-NaAn-1-PNa: 4% 3 Me-1 Bu-TPPDA (20 nm)/LG201 + 80% 8-quinolinolto lithium (Liq) (24 nm)/LiF/Al. HAT-CN, MHT210, and MEB310 were used as the HIL, HTL, and electron blocking layer (EBL), respectively. Liq-doped LG201 was used as the ETL, while LiF was used as the EIL in doped OLED device. The LiF and Al layers were sequentially deposited under identical vacuum conditions.