Aqueous synthesis of 79efficient AgInGaS/ZnS quantum dots for extremely high color rendering white light-emitting diodes

摘要

Over the past few decades,I-III-VI quantum dots(QDs)have attracted considerable attention due to their large Stokes shifts,good eco-friendliness,and wide tunable emissions.In this work,a facile microwave-assisted aqueous route using glutathione(GSH)and citric acid(CA)as dual stabilizers is introduced to synthesize AgInGaS/ZnS(AIGS/ZnS)core/shell QDs.An exceptional photoluminescence quantum yield(PL QY)as high as 79%is successfully achieved,boosting the best performance of water-dispersible AIGS QDs.By varying the Ag/Ga ratio,the PL peak wavelength can be tuned from 547 to 616 nm,and luminescent hydrogel films with different colors are obtained by embedding AIGS/ZnS QDs in polyacrylamide/poly-vinyl alcohol(PAAm/PVA)hydrogels.The white light-emitting diode(WLED)with a high color rendering index(CRI)of 92.1(R_(9)=92.0)and a correlated color temperature(CCT)of 3022 K is fabricated using QDs-PAAm/PVA hydrogel films in combination with a blue InGaN LED chip,indicating that the as-prepared QDs are competitive color-conversion materials for WLEDs.