Comment on “High‐Efficient Blue Emission and Bandgap Engineering from Jahn‒Teller Distorted Halide Double Perovskites”

In a recent publication, Liu et al. investigated the doping strategy of pentavalent antimony (Sb 5+ ) in the benchmark material Cs 2 NaInCl 6 , achieving a bright blue emission with a high photoluminescence quantum yield of ≈90% at low doping concentrations and bandgaps as low as 1.24 eV at high doping concentrations ( Adv. Opt. Mater . 2024, 12 , 2301576). In this comment, by reanalyzing Liu et al.' data and conducting hybrid density functional theory calculations, the study provides evidence supporting the incorporation of Sb 3+ ions rather than “Sb 5+ ions”, as the cause of the efficient blue emission observed in the lightly‐doped Cs 2 NaInCl 6 samples. Furthermore, it is proposed that the narrowing of the bandgap in the “heavily‐doped Cs 2 NaInCl 6 ” samples is a result of the formation of a new phase related to a mixed‐valence salt, Cs 4 Sb III Sb V Cl 12 .