Light-Induced Photoluminescence Switching Using Liquid Crystal-Dispersed Quantum Dots

Light-induced photoluminescence (PL) switching using azobenzene-doped liquid crystal (LC)-dispersed quantum dots (QDs) is demonstrated in a format of LC cell and LC-infiltrated tube. Before light irradiation, excitation photons undergo multiple scattering events before emission out of the LC cell, and PL intensity is high. Upon the light irradiation, the trans-to-cis photoisomerization of azobenzene makes the QD-dispersed LCs highly transparent, thus allowing most excitation photons to pass through LCs and decrease PL intensity. This demonstration may allow a new modulating technique for future development of light-switchable, QD-emission-based display or photonic devices.