Both Luminous Efficiency and Lifetime Enhancement in Blue Fluorescence OLEDs by Modifying Molecular Structure of Hole Transporting Material

Abstract

Both luminous efficiency and lifetime in blue fluorescence organic light emitting devices (OLEDs) have been improved by modified HTMs with higher LUMO energy levels. The LUMO energy levels of HTM were increased by modifying substituent in HTM molecules. Two HTMs containing ortho and meta biphenyl substituent and one HTM containing thiophene substituent were synthesized via palladium catalyzed amine coupling reactions to compare with a para biphenyl substituent HTM-1 as a standard molecule. According to TDDFT calculations, these three modified HTMs showed 0.05-0.15 eV higher LUMO energy levels compared to the para biphenyl substituent HTM-1. The luminous efficiency and the lifetime (LT90) of OLEDs using HTM-2 at 500 cd/m 2 have been enhanced up to 20 % and 52 %, respectively, compared to the standard device using HTM-1.

Silver Nanoparticles with Dual-Recognition via CRISPR/dCas9 for SERS Identification of Two KRAS Mutations in Nucleic Acid Targets

“…In order to explore the sensing response of the assay toward the two target DNA fragments, two types of SERS nanotags equipped with different Ra molecules, MBN and TFMBA, were used to label the G12C and G12V mutant DNAs, respectively. As shown in Figure A, all SERS spectra show three sets of fingerprint peaks for MBN, including a double peak due to the in-plane bending modes located at ∼1095 and ∼1185 cm –1 , a vibration mode of phenyl ring centered at 1580 cm –1 , and a ∼2200 cm –1 band generated from the CN stretching . The intensity of this series of peaks increases with the concentration of G12C DNA from 3.60 × 10 –9 to −1.80 × 10 –8 M, indicating that the G12C DNA fragments were collected by CRISPR/dCas9@MB and subsequently labeled by the SERS nanotag.…”

“…As shown in Figure 5A, all SERS spectra show three sets of fingerprint peaks for MBN, including a double peak due to the in-plane bending modes located at ∼1095 and ∼1185 cm −1 , a vibration mode of phenyl ring centered at 1580 cm −1 , and a ∼2200 cm −1 band generated from the CN stretching. 33 The intensity of this series of peaks increases with the concentration of G12C DNA from 3.60 × 10 −9 to −1.80 × 10 −8 M, indicating that the G12C DNA fragments were collected by CRISPR/dCas9@MB and subsequently labeled by the SERS nanotag. As the characteristic peak at 1580 cm −1 is the largest, it was used to plot the SERS signal intensity versus the G12C amount.…”