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

Abstract In a recent publication, Liu et al. investigated the doping strategy of pentavalent antimony (Sb⁵⁺) in the benchmark material Cs₂NaInCl₆, 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 Sb³⁺ ions rather than “Sb⁵⁺ ions”, as the cause of the efficient blue emission observed in the lightly‐doped Cs₂NaInCl₆ samples. Furthermore, it is proposed that the narrowing of the bandgap in the “heavily‐doped Cs₂NaInCl₆” samples is a result of the formation of a new phase related to a mixed‐valence salt, Cs₄Sb^IIISb^VCl₁₂.