posted on 2021-12-10, 15:06authored byGuanwei Liang, Yong Tang, Peisen Chen, Jiasheng Li, Yikai Yuan, Shudong Yu, Liang Xu, Zongtao Li
High-haze optical polymer diffusers
have attracted great attention
in terms of application in surface color-conversion films for lighting
and displays. An optical diffuser based on polystyrene-fiber rods
(PFRs) dispersed in polydimethylsiloxane (PDMS) resin is presented
in this study. Using a simple electrospinning and emulsion shear fabrication
process, composite films having optical diffusion properties were
fabricated owing to index-mismatching between the PFRs and PDMS. During
mechanical shearing, it is demonstrated that the rotation speed is
the important parameter affecting the length of the PFRs. PFRs are
uniformly dispersed in the PDMS matrix as an excellent filler to provide
excellent light-scattering performance. The obtained composite films
having low concentrations of PFRs (less than 1 wt %) exhibit highly
efficient light diffusion in the visible-light region. At a 0.5 wt
% PFR concentration, the composite film realizes a high haze of 87.4%
while maintaining a high diffuse transmittance of 81.8% at 550 nm
simultaneously. The PFRs were then filled in the quantum dot (QD)
films for enhancing the photoluminescence (PL) intensity, thus demonstrating
their light management ability. Compared to the reference, the PFRs/PDMS
film with a 1 wt % concentration provides a 1.98 times PL intensity
enhancement. While applying to the QD-based LEDs, the luminous flux
of the QD-based LEDs exhibited the greatest improvement, demonstrating
an enhancement of 11.37% at a 0.4 wt % PFR concentration. It exhibits
potential for optical performance improvement in QD-based light-emitting
diodes.