Synthesis of highly fluorescent InP/ZnS small-core/thick-shell tetrahedral-shaped quantum dots for blue light-emitting diodes

Abstract

Blue light-emitting diodes (LEDs) offer new opportunities in practical solid-state lighting and could play a significant role in reducing global energy consumption. Here, for the first time, we report the synthesis of highly fluorescent InP/ZnS small-core/thick-shell tetrahedral shaped QDs for blue LED applications. These QDs have absolute fluorescence quantum yield (QY) up to 76%, along with a full width at half-maximum as narrow as 44 nm and a prolonged photoluminescence lifetime of above 60 ns, which are records for blue InP QDs. In addition, these small-core/thick-shell QDs show improved stability for over 1000 hours of storage under ambient conditions. Correspondingly, blue LED devices with a maximum luminance of 90 cd m⁻² were successfully demonstrated using InP/ZnS QDs as the active layer. This work may pave the way for the development of next generation environmentally friendly blue light sources using heavy-metal-free QDs with high efficiency, high color purity and high stability.