A molecular-based aggregation engineering strategy for high-efficiency deep-blue phosphors

Abstract

Deep-blue emissive phosphors play a crucial role in fabricating phosphor-converted light-emitting diodes (pc-LEDs). Although solid-state luminescence technology has made significant progress, challenges still remain in achieving high-efficiency emission in the deep-blue spectral region. In this work, through spatial rigidity engineering to suppress the non-radiative transition process, we developed a highly efficient deep-blue emission system. In this system, boric acid (BA) was used as the matrix and 1-naphthoic acid (NAPA), an aggregation-induced emission (AIE) molecule, was employed as the fluorophore. By the incorporation of electron donor o-phenylenediamine (OPD) into the system promoted a transition of NAPA from J-aggregation to H-aggregation, effectively broadening the tunable range of fluorescence emission spectra. It’s found that the synergistic effects of hydrogen bonding interactions and the AIE mechanism enabled continuously tunable luminescent materials within the deep-blue range (406 nm to 430 nm), with a maximum quantum yield (QY) of 89.1 %. Exciting the deep-blue phosphor with a 365 nm chip resulted in bright blue light with CIE chromaticity coordinates of (0.155, 0.071) under a drive current of 60 mA. This study introduces a simple and universal method to fabricate solid-state phosphors with emission-tunable properties via molecule-based aggregation engineering, effectively overcoming the limitations of spectral rigidity and poor adaptability to diverse application scenarios in current deep-blue materials.