Synthesis of Highly Luminescent InP/ZnS Quantum Dots with Suppressed Thermal Quenching

InP quantum dots (QDs) are promising down-conversion phosphors for white light LEDs. However, the mainstream InP QDs synthesis uses expensive phosphorus source. Here, economic, in situ-generated PH3 is used to synthesize InP QDs and a two-step coating of ZnS shells is developed to prepare highly luminescent InP/ZnS/ZnS QDs. The QDs show a photoluminescence quantum yield as high as 78.5%. The emission can be tuned by adjusting the halide precursor and yellow emissive InP/ZnS/ZnS QDs are prepared by judiciously controlling the synthetic conditions. The yellow QDs show suppressed thermal quenching and retain >90% room temperature PL intensity at 150 degrees C for the growth solution. Additionally, the PL spectrum matches with the eye sensitivity function, resulting in efficient InP QD white light LEDs.

Automated summary

In this study, an economic method using in situ-generated PH3 to synthesize InP QDs and a two-step coating of ZnS shells to prepare highly luminescent InP/ZnS/ZnS QDs are developed. The emission of the QDs can be tuned by adjusting synthetic conditions to prepare yellow emissive QDs, which show high photoluminescence intensity even at high temperatures.