# Highly Efficient Blue Host Compound Based on an Anthracene Moiety for OLEDs
## 4 Conclusions  
We synthesized a novel blue host material, 2-NaAN-1-PNa, which, owing to its asymmetric structure, effectively prevents molecular packing in the solid state and provides steric hindrance to form thermally stable amorphous films. Consequently, it exhibited excellent thermal properties with a T\({}_{g}\) value exceeding 130 \({}^{\circ}\)C. The doped device utilizing 2-NaAn-1-PNa as the host showed a low O.V. of 3.9 V at 10 mA/cm\({}^{2}\) and emitted light in the real blue region with CIE coordinates of (0.134, 0.139) and a peak wavelength of 460 nm. It demonstrated a CE of 9.3 cd/A, an EQE of 8.3%, and a luminance of 934 cd/m\({}^{2}\). Regarding EQE roll-off, it exhibited a very low level of roll-off, reaching only 1.9% at 4000 nits. The LT\({}_{95}\) measurement for OLED device lifetime was approximately 440 h. With its high efficiency and longevity, 2-NaAn-1-PNa shows promise for various display applications.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app14135716/s1](https://www.mdpi.com/article/10.3390/app14135716/s1)]([https://www.mdpi.com/article/10.3390/app14135716/s1](https://www.mdpi.com/article/10.3390/app14135716/s1)), Figure S1: 1H-NMR spectrum of compound **(1)**; Figure S2: 1H-NMR spectrum of compound **(2)**; Figure S3: 1H-NMR spectrum of 2-NaAn-1 PNa; Figure S4: Transient PL spectrum of 2-NaAn-1-PNa in solution state (10\({}^{-5}\) M in toluene).;  
Figure 6: EL characteristics of doped device using 2-NaAn-1-PNa: 4 wt% 3 Me-1 Bu-TPPDA: (**a)** J-V-L curve (left arrow: current density, right arrow: luminance), (**b**) luminance efficiency versus current density, (**c**) external quantum efficiency versus current density, (**d**) EL spectrum of OLED doped device at 10 mA/cm\({}^{2}\), and (**e**) energy level diagrams of the fabricated doped OLED device.  
Figure 7: Device lifetime of OLED doped device.  
Figure 55: PL spectrum of 3 Me-1 Bu-TPPDA in solution state (10\({}^{-5}\) M in toluene).; Figure S6: Cyclic voltammograms under 100 mV/s of 2-NaAn-1-PNa [0.1 M TRAP-F6 in dichloromethane reference electrode: Ag/AgCl].; Figure S7: Chemical structures of materials used for OLED devices fabrication. Figure S8: Thickness profile images (a) 2-NaAn-1-PNa evaporated film (thickness: 35 nm), (b) 2-NaAn-1-PNa: 4% 3 Me-1 Bu-TPPDA evaporated film (thickness: 20 nm); Table S1: Photophysical properties of the synthesized compound; Table S2: Thermal properties of the synthesized materials.  
Conceptualization, H.K. and S.O.; methodology, H.K.; validation, H.L. and J.P.; formal analysis, S.P. (Sunwoo Park) and H.L.; investigation, S.P. (Sangwook Park) and S.O.; resources, J.P.; writing--original draft preparation, H.K., S.O. and J.P.; writing--review and editing, H.L. and J.P.; visualization, H.K., S.P. (Sangwook Park) and S.P. (Sunwoo Park); supervision, J.P.; project administration, J.P.; funding acquisition, J.P. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the GRRC program of Gyeonggi province. [(GRRCKYUNGH EE2023-B01), Development of ultra-fine process materials based on the sub-nanometer class for the next-generation semiconductors].  
Not applicable.  
Data availability Statement: Data are contained within the article and Supplementary Materials.  
The authors declare no conflicts of interest.