Highly Stable CsPbBr₃ Perovskite Quantum Dots with ZnS Shells from Single-Molecule Precursors for Optoelectronic Devices

Abstract

Perovskite quantum dots (PQDs) are known for their exceptional tunable color emission and narrow spectral width, distinguishing them from light emitters. However, the stability of CsPbBr3 PQDs against environmental factors remains a major challenge. This work aims to address the stability issues of CsPbBr3 PQDs by synthesizing an inorganic zinc sulfide (ZnS) shell using single-molecular precursors at low temperatures in a single-step synthesis approach. The synthesized inorganic ZnS shell provides remarkable stability against environmental factors, such as water, light, and heat. The CsPbBr3/ZnS core/shell PQDs exhibited a narrow full width at half-maximum of 16.5 nm, an improved quantum yield of 97%, double average fluorescence lifetime, and stability against halide exchange. The ZnS shelling is confirmed by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy analysis. We achieved the dispersion of our PQDs in green solvent stabilizing with mono-2-(methacryloyloxy)­ethyl succinate in a solution phase-ligand displacement process. Our core/shell PQDs produce high-resolution patterning through a thiol–ene reaction in a direct patterning process. These findings create a gateway for our core/shell PQDs use in stable optoelectronic devices like displays and perovskite light-emitting diodes.