Development of SnS/PVP core/shell quantum dots with tunable color emission synthesized by microwave heating.

Tin sulfide (SnS) is an earth-abundance material of non-toxic nature compared to commercially available quantum dots (QDs). Herein, a novel strategy is reported to improve the spectral tunability and stability of SnS/polyvinylpyrrolidone (PVP) core/shell QDs via microwave irradiation synthesis. Although PVP is used as a capping agent and passivating ligand for SnS QDs, as reported elsewhere, we take advantage of its polarity that allows good interaction with microwave irradiation, which impacts the nucleation and growth of SnS QDs. Furthermore, the amount of PVP in the precursor solutions controls the surface states and color purity of the QDs, and the obtained SnS/PVP QDs exhibit color-tunable emission light from blue to orange. The photoluminescence quantum yield reached the highest reported for SnS QDs, whereas 50% of their fluorescence intensity was maintained after 1-year storage at daylight. This approach provides a synthetic route to produce tunable and efficient colloidal QDs. A novel strategy using different polyvinylpyrrolidone (PVP) concentration to control the PVP shell thickness of SnS quantum dot cores, to improve the spectral tunability and stability of SnS/PVP core/shell QDs via microwave irradiation synthesis. With a range of diameters of those SnS/PVP core/shell QDs from 4.29 to 10.53 ​nm [Display omitted]. • Tuning of SnS QDs size by increasing PVP amount in microwave synthesis. • Color-tunable emission from blue to orange light under UV light by SnS/PVP QDs. • FRET is achieved through coupling the PVP chains with SnS cores, reached a high quantum yield. • The optimized PVP thickness gives high color purity and stability of SnS/PVP QDs. [ABSTRACT FROM AUTHOR]