Elucidation of the structural and optical properties of metal cation (Na⁺, K⁺, and Bi³⁺) incorporated Cs₂AgInCl₆double perovskite nanocrystals

Abstract

Potassium substituted double perovskite nanocrystals of the form Cs2KxAg1−xInCl6:Bi (x = 0–1) exhibit improved PLQY behaviour and structural diversity.

“Green” synthesis of highly luminescent lead-free Cs2AgxNa1−xBiyIn1−yCl6 perovskites

“…1,4 The interest in such compounds, particularly in Bi-doped Cs 2 Ag x Na 1− x InCl 6 (referred to as CANIC) or Cs 2 Ag x Na 1− x Bi y In 1− y Cl 6 (referred to as CANBIC), is constantly growing due to their intense broadband photoluminescence (PL) combined with a unique tunability of the photophysical properties and an outstanding chemical stability. 5–21…”

A powder XRD, solid state NMR and calorimetric study of the phase evolution in mechanochemically synthesized dual cation (Csx(CH3NH3)1−x)PbX3 lead halide perovskite systems

“…Variation in the in dipolardominated 133 Cs T 1 s have been previously used as diagnostic probes of mobility, dynamics and phase transitions in halide perovskite materials. 18,[43][44][45][46] The measured reduction in 133 Cs spin-lattice relaxation rates have been correlated to phase transitions and associated increase in electrical conductivity due to increase in halide mobility. 44,47 Fig.…”

Cs2AgxNa1−xBiyIn1−yCl6 perovskites approaching photoluminescence quantum yields of 100%

“…2b) with the lattice parameter increasing from 10.515(2) Å for CANIC (y = 0) to 10.823(2) Å for CANBC (y = 1.0) reflecting the gradual lattice expansion due to the larger ionic radius of Bi 3+ as compared to In 3+ 17,18,20,26,28,32 . The linear character of L(y) obeying Vegard's law shows that the CANBIC perovskites are ideal solid solutions and form a single phase for any possible composition 20,21,26,28,29,32 . The results of the Rietveld refinement of the XRD patterns of 10 different CANBIC compositions are presented in SI (Fig.…”

“…on the ratios of Ag/Na and Bi/In 17,18,20,21,23,34 . For example, CANBIC compounds often show exceptionally strong dependence of the PL quantum yield (QY) and Huang-Rhys factor on the Ag-to-Na ratio x 18,21,25,[28][29][30]32,34 , while CANBICs with a fixed x typically reveal a dome-shaped dependence of the PL efficiency on the Bi fraction y 17,18,31,32,34,41 . Along with the variable parameters x and y, both Cs and Cl sites can also be varied and potentially substituted by analogs (for example, Cs by Rb or methylammonium).…”

“…Among the double halide perovskites, compounds based on Bi III and In III with a general formula Cs 2 Ag x Na 1− x Bi y In 1− y Cl 6 (abbreviated as CANBIC by the first letters of the elements) occupy an outstanding position due to a combination of the compositional variability, stability, and promising light-conversion properties, in particular, highly efficient broadband photoluminescence (PL). 12,13,15,17–42 These compounds typically feature a dome-shaped dependence of many photophysical characteristics (PL efficiency and lifetime, electron–phonon coupling strength, etc. ) on the ratios of Ag/Na and Bi/In.…”