Sb-Doped Metal Halide Nanocrystals: A 0D versus 3D Comparison

We synthesize colloidal nanocrystals (NCs) of Rb3InCl6, composed of isolated metal halide octahedra (0D), and of Cs2NaInCl6 and Cs2KInCl6 double perovskites, where all octahedra share corners and are interconnected (3D), with the aim to elucidate and compare their optical features once doped with Sb3+ ions. Our optical and computational analyses evidence that the photoluminescence quantum yield (PLQY) of all these systems is consistently lower than that of the corresponding bulk materials due to the presence of deep surface traps from under-coordinated halide ions. Also, Sb-doped 0D Rb3InCl6 NCs exhibit a higher PLQY than Sb-doped 3D Cs2NaInCl6 and Cs2KInCl6 NCs, most likely because excitons responsible for the PL emission migrate to the surface faster in 3D NCs than in 0D NCs. We also observe that all these systems feature a large Stokes shift (varying from system to system), a feature that should be of interest for applications in photon management and scintillation technologies. Scintillation properties are evaluated via radioluminescence experiments, and re-absorption-free waveguiding performance in large-area plastic scintillators is assessed using Monte Carlo ray-tracing simulations.

Automated summary

Colloidal nanocrystals of Rb3InCl6 and double perovskites of Cs2NaInCl6 and Cs2KInCl6 were synthesized for optical analysis, revealing lower photoluminescence quantum yield in 3D Cs2NaInCl6 and Cs2KInCl6 NCs compared to 0D Rb3InCl6 NCs when doped with Sb3+ ions. All systems exhibited a large Stokes shift, making them potentially valuable for photon management and scintillation technologies. Scintillation properties were evaluated through radioluminescence experiments, and waveguiding performance in plastic scintillators was assessed using Monte Carlo ray-tracing simulations.