The halide double perovskite solid solution Cs2AgBiBr6−xClx has been investigated and found to exhibit a band gap that increases from 2.2 eV to 2.8 eV as the Cl− content increases, with an upward deviation from Vegard's law when x > 5.
Correction for ‘Cs2NaGaBr6: a new lead-free and direct band gap halide double perovskite’ by Yasir Saeed et al., RSC Adv., 2020, 10, 17444–17451, DOI: 10.1039/D0RA01764G.