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, Cs4SbIIISbVCl12.

Band gap engineering and photoluminescence tuning in halide double perovskites

“…40 However, this interpretation is challenged in a recent comment by Xiao, who argues that the observed band gap narrowing is likely due to the formation of a side product Cs 4 Sb III Sb V Cl 12 rather than the intrinsic properties of the doped Cs 2 NaInCl 6 material. 41…”