Competitive Interfacial Etching and Growth for Multicolor-Tunable Circularly Polarized Luminescent Quantum Dots

Abstract

Circularly polarized luminescence (CPL) provides an additional optical degree of freedom beyond conventional wavelengths and intensities, offering new opportunities for advanced photonic technologies. However, the rational construction of semiconductor nanocrystals with strong CPL remains challenging, largely due to the lack of an understanding of how inorganic chirality is generated and coupled with excitonic emission. Here, we demonstrate that nanocrystal interfaces can serve as dynamic platforms for constructing inorganic chirality through coupled interfacial chemical equilibria. Using InP@ZnS quantum dots (QDs) as a model system, we reveal that pH regulation redistributes the balance between Zn-mediated interfacial etching and ZnS epitaxial growth by simultaneously tuning Zn coordination and sulfur precursor release kinetics, thereby directing the evolution of the inorganic structure and chiroptical properties. This interfacial regulation enables multicolor emission tuning from 524 to 596 nm while maintaining a photoluminescence quantum yield of 56.18% and achieving a high luminescence dissymmetry factor of 0.022. Atomic-scale structural analysis reveals that interfacial reactions introduce symmetry breaking and lattice distortion within InP@ZnS nanocrystals. Further electronic structure analysis shows that the heterovalent interface promotes directional charge redistribution, which strengthens the interaction between the distorted inorganic structure and the excitonic transitions. By integration of tunable emission and polarization-dependent optical responses, these CPL QDs further enable multidimensional optical encryption. This work establishes nanocrystal interfaces as programmable platforms for constructing inorganic chirality and enabling CPL-active semiconductor nanocrystals.