Improved Energy Transfer in Mn-Doped Cs₃Cu₂I₅ Microcrystals Induced by Localized Lattice Distortion

Abstract

With nontoxicity and high emission efficiency, luminescent copper­(I)-based halides have attracted much attention as alternatives for lead-based perovskites in photoelectric domains. However, extending the emission wavelength by doping with Mn2+ in a facile way is still a challenge. In this work, Mn2+-doped Cs3Cu2I5 microcrystals were synthesized by a mild solution method, and double emission bands from self-trapped excitons (STEs) and Mn2+ peaking at 445 and 560 nm, respectively, were observed. More importantly, further introduction of alkali metal ions (Rb+, K+, Na+) considerably promoted the luminescence performance of the Cs3Cu2I5–Mn microcrystals. The STE → Mn2+ energy transfer efficiency of the typical sample doped with Na+ increased from ∼0 to 21.30%, and the photoluminescence quantum yield (PLQY) increased from 47.32% to 62.06%. The detailed structural and optical characterizations combined with DFT calculations proved that the doping with alkali metal ions causes lattice distortion and enhances the coupling between [MnI4] and [CuI4] tetrahedra, thus promoting the energy transfer efficiency and the PLQY.

All-inorganic copper-halide perovskites for large-Stokes shift and ten-nanosecond-emission scintillators

“…Herein, we evaluate the presence of multiple STEs in CHPs from the theoretical 61,85–88 perspectives and experimental findings 49 that are mainly governed by the direct consequence of exciton localisation and excited-state structural reorganization. 89 As the latter, the energetic positions can be modulated by altering the halogen composition of spatially isolated Cu-X polyhedra via rational design.…”

Enhancing Photoluminescence and Stability of Mn-Doped Cs2InCl5·H2O Microcrystals with Introduced Bi3+ Ion

“…With rising Bi 3+ concentration, the average lifetime of Mn 2+ increased from 6.0 μs for single Mn 2+ -doped MCs to 21.0 μs for Cs 2 In 0.45 Bi 0.55 Cl 5 ·H 2 O:17%Mn MCs and has a variation tendency similar to its emission intensity. The prolonged Mn 2+ lifetime could be assigned to the ET from the [BiCl 6 ] 3– unit, which acts as UV light absorber and exciton donor, to [MnCl 6 ] 4– and results in the enhanced concentration of electrons in the excited state, improving the 4 T 1g – 6 A 1g transition process in Mn 2+ . ,− …”

Cost-effective screen printing approach for Ce/Nd-doped ZnAl2O4 films: tuning crystallinity induced by the substrate

“…23 Other strategies, such as the introduction of alkali metal ions, can also considerably promote luminescence performance. 24 Our recent study demonstrates that the ZnAl 2 O 4 is a suitable matrix for both dopants. 25 However, the host ZnAl 2 O 4 , which is known as a catalytic material, is transparent conductive oxide and sintering additive.…”