Design Optimization of Lead-Free Perovskite Cs₂AgInCl₆:Bi Nanocrystals with 11.4% Photoluminescence Quantum Yield

Abstract

Lead-free halide double perovskites continue to draw increasing attention in view of their nontoxicity and stability compared to lead-based perovskites. Herein, we optimized the colloidal synthesis of undoped and Bi-doped Cs2AgInCl6 nanocrystals (NCs) via the facile hot-injection process using nontoxic and available precursors. The synthesis conditions including temperature, ligands, and hydrochloric acid are investigated to boost the photoluminescence quantum yield (PLQY) of Cs2AgInCl6:Bi NCs with the trace amount of Bi doping. The broad-band orange emission peaking at 580 nm is observed with the PLQY as high as ∼11.4%, and the related luminescence mechanism has been discussed. This work provides a reliable avenue toward the optimization of optical properties for emerging lead-free halide perovskite NCs with enhanced PLQY.

Lead‐Free Sodium–Indium Double Perovskite Nanocrystals through Doping Silver Cations for Bright Yellow Emission

“…1.6 %). [22] Thei mprovement of photoluminescence (PL) properties by multivalent cation (Mn 2+ or Bi 3+ )d oping has been widely concerned, [22,23,26] but the mechanism of little PL emission is still unclear in direct band gap DP NCs.T oo ur knowledge,t hus far,t here is no report about all-inorganic Cs 2 NaInCl 6 DP NCs.…”

“…Although Cs 2 AgInCl 6 NCs have been synthesized by using other constant temperature synthetic routes (optimizing precursor type), the morphology of these NCs is not very regular and they have phase separation (there are lots of black spots in TEM images). [22,23,[26][27][28] Thev ariable temper-ature hot injection is superior to conventional hot injection for In-based DP NCs synthesis,and suitable for the synthesis of other lead-free perovskites NCs ( Figure S1-S10 in the Supporting Information). TheC s 2 NaInCl 6 NCs are synthesized by variable temperature one-pot hot injection.…”

Recent Developments in Lead‐Free Double Perovskites: Structure, Doping, and Applications

“…The possibility of this emission because self‐trapped excitons originate from the Jahn–Teller distortion of the [Ag I Cl 6 ] octahedron in the excited state . Liu et al . further observed the effect of HCl amount on phase stability and purity.…”

“…Liu et al . used a solution‐processed hot injection method to doping trivalent Bi 3+ into the direct band gap Cs 2 AgInCl 6 and achieved a photoluminescence quantum yield of up to 11.4 % as shown in Figure B.…”

“…discussed recent theoretical and experimental research on electronic, optical, and defect properties. Numerous developments have recently happened on double perovskite structure research in terms of different synthesis methods, doping to improve stability, and tuning the emission from the visible to the infrared region . The double perovskite structure has also been applied for humidity sensors, X‐ray detectors, and photocatalysts (dye degradation, CO 2 reduction) and should be discussed comprehensively.…”