Cu–In–S/ZnS Quantum Dots Embedded in Polyvinylpyrrolidone (PVP) Solids for White Light-Emitting Diodes (LEDs)

Abstract

Here, we report a facile and green route to prepare Cu–In–S (CIS)/ZnS core/shell quantum dots (QDs) embedded in polyvinylpyrrolidone (PVP) solids and their application as phosphors for white light-emitting diodes (WLEDs). CIS/ZnS core–shell QDs were easily synthesized in the aqueous phase, assisted by microwave irradiation within 20 min at 95 °C. The emission wavelength of CIS/ZnS QDs could be tunable between a large range of 543–700 nm by adjusting the [Cu]/[In] ratios, and the photoluminescence (PL) quantum yield could be up to 43% by coating a ZnS layer. QD-embedded PVP solids then were facilely fabricated by mixing CIS/ZnS QDs and PVP in water, followed by drying, to show improved PL intensity, higher photostability, and higher thermostability. Finally, we demonstrated their potential application as a white light source by using green- and red-emitting CIS/ZnS/PVP nanocomposite solids as color converters, in combination with a blue light-emitting diode (LED) chip.