Efficient organic deep-red to near-infrared light emitters based on boron difluoride curcuminoid derivatives

Organic light-emitting materials in the near-infrared (NIR) region are important for lightweight and wearable medical and military device applications. However, there has been little development of highly efficient NIR light-emitting materials made of purely organic small molecules. This paper introduces tBuPZ and PZ, two novel deep-red to NIR light-emitting curcuminoid boron difluoride derivatives with phenothiazine moiety, to demonstrate organic light-emitting diodes with a maximum external quantum efficiency of 4.11% and 3.92%, respectively, and electroluminescence at 618 nm, with a shoulder peak at 673 nm. By analyzing the donor characteristics of di-tert-butyl substitution, the correlations between electron-donating strength, the emission mechanism, and quantum efficiency were investigated. This study presents a methodology for the design of low toxicity, dye-derived, purely organic NIR light-emitting molecules.

Automated summary

This study introduces two novel deep-red to near-infrared (NIR) light-emitting curcuminoid boron difluoride derivatives, tBuPZ and PZ, for organic light-emitting diodes. The maximum external quantum efficiency achieved was 4.11% and 3.92%, respectively, with electroluminescence at 618 nm and a shoulder peak at 673 nm. The correlations between electron-donating strength, emission mechanism, and quantum efficiency were investigated by analyzing the donor characteristics of di-tert-butyl substitution. This study presents a methodology for designing low-toxicity, dye-derived, purely organic NIR light-emitting molecules.