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.
Stable double perovskite Cs2AgInCl6 has been reported as a direct gap semiconductor with a wide band gap of 3.23 eV obtained experimentally and 3.33 eV obtained by DFT calculation.
Lead-based halide perovskite nanocrystals (NCs) are recognized as emerging emissive materials with superior photoluminescence (PL) properties. However, the toxicity of lead and the swift chemical decomposition under atmospheric moisture severely hinder their commercialization process. Herein, we report the first colloidal synthesis of lead-free Cs4CuIn2Cl12 layered double perovskite NCs via a facile moisture-assisted hot-injection method stemming from relatively nontoxic precursors. While moisture is typically detrimental to NC synthesis, we demonstrate that the presence of water molecules in Cs4CuIn2Cl12 synthesis enhances the PL quantum yield (mainly in the near-UV range), induces a morphological transformation from 3D nanocubes to 2D nanoplatelets, and converts the dark transitions to radiative transitions for the observed self-trapped excitons relaxation. This work paves the way for further studies on the moisture-assisted synthesis of novel lead-free halide perovskite NCs for a wide range of applications.
Cs2NaGaBr6: a new lead-free and direct band gap halide double perovskite