Reduced working temperature of quantum dots-light-emitting diodes by QDs@silica-on-chip structure

Quantum dots-converted white light-emitting diodes (QDs-WLEDs) are considered as next generation artificial light source by virtue of high luminous efficiency (LE) and excellent color rendering index (CRI). While, QDs' poor temperature stability and the incompatibility of QDs/silicone severely hinder the wide utilization of QDs-WLEDs. To relieve these problems, here we proposed a separated QSNs/phosphor structure, composed of a QSNs-on-chip layer with a yellow phosphor layer above. A silica shell was coated onto the QDs surface to solve the compatibility problem between QDs and silicone. With CRI > 92 and R9 > 90, the newly proposed QDs@silica nanoparticles (QSNs) based WLEDs present 16.7 % higher LE and lower QDs working temperature over conventional mixed type WLEDs. The reduction of QDs' temperature can reach 11.5 °C, 21.3 °C and 30.3 °C at driving current of 80 mA, 200 mA and 300 mA, respectively.