1 research outputs found
Exceeding 67.35% Efficient and Color Temperature Tunable White Light from Carbon Dots with Quadruple-Channel Fluorescence–Phosphorescence Emission
Luminescent carbon dots (CDs) have drawn much attention
in terms
of photoelectronic applications, most of which are focused on single-component
white-light emission. However, it still remains a significant challenge
to create high-quality white-light-emitting CDs with tunable correlated
color temperatures (CCTs). The theoretical calculation is initially
used to predict that the enlargement of the conjugated sp2 domain induces redshift fluorescence (FL) and room temperature
phosphorescence (RTP) emissions of CDs. Guided by the theoretical
predictions, single-component white-light emission from CDs with high
efficiency of 67.35% and tunable CCTs from 10,803 to 3376 K is realized.
These CDs exhibit quadruple-model emissions with hybrid FL/RTP components
at 435 nm (FL-1)/548 nm (RTP-1) and 461–522 nm (FL-2)/525–610
nm (RTP-2), which originate from a synergy between certain P bonds
with aggregation-induced emission effects and different sizes of sp2 conjugated structures, respectively. Using
such CDs as conversion phosphors, we prepared three white-light-emitting
diodes (WLEDs) which can emit bright cool, standard, and warm white
lights with color rendering indices of 81–85. Finally, highly
luminescent WLEDs are also developed by dispersing these CDs in a
poly(vinyl alcohol) matrix, indicating that this provides an industrial
application potential