Isoreticular Postsynthetic Modification of Robust Organocopper(I) Halide Hybrids for Enhanced Broad-Band Emission and Turn-On NH₃ Sensing

Abstract

Organometal halide hybrids are an emerging class of single-component white-light emitters originating from selftrapped excitons (STEs), showing many promising attributes such as intrinsic nature and a high color-rendering index (CRI). However, one challenge is to develop rational synthetic strategies to tune the photoluminescence properties on a molecular level. Herein, for the first time, we report the isostructural postsynthetic incorporation of NH 3 into organometal halide crystalline materials to enhance the STE-based warm white-light emission, affording substantially increased photoluminescence quantum yields (PLQYs) from 5−5.5 to 60−75%. The NH 3 -incorporated Cu I − halide hybrids are rare examples of lead-free single-component yellowish white-light emitters with high PLQYs and a high CRI of 64−72. The single-crystal-to-single-crystal transformation is monitored by X-ray crystallography and density functional theory calculations, suggesting that the incoming NH 3 molecules serve as spacers to isolate linear Cu I −halide species at the excited state to facilitate the exciton confinement. Moreover, the precise modification process is highly reversible and selective over many common gaseous molecules or other amines. The organocopper(I) halide hybrids also feature high structural and emissive stabilities for at least 18 months in air at room temperature, affording a high potential for commercial uses in solid-state lighting. This study demonstrates a potentially general strategy to enhance the STE emission on the molecular level.

Organolead Halide-Based Coordination Polymers: Intrinsic Stability and Photophysical Applications

“…Recently, our group has successfully synthesized a few lead-free halide coordination polymers based on 1D [CdCl] + and 1D [Cu 2 X 2 ] (X = Cl − /Br − ) chains. 54,55 A positive sign is that both of them exhibit intrinsic broadband self-trapped emission, which is analogous to the lead counterpart. Third, visible-light absorption of the halide coordination polymers needs to be considerably improved.…”

“…Second, considering the toxicity of Pb 2+ , developing the synthetic approach to less toxic metal-based (e.g., Cu + , Ag + , Sn 2+ and Bi 3+ ) halide coordination polymers is crucial for practical utilization. Recently, our group has successfully synthesized a few lead-free halide coordination polymers based on 1D [CdCl] + and 1D [Cu 2 X 2 ] (X = Cl – /Br – ) chains. , A positive sign is that both of them exhibit intrinsic broadband self-trapped emission, which is analogous to the lead counterpart. Third, visible-light absorption of the halide coordination polymers needs to be considerably improved.…”

Stable self-trapped broadband emission from an organolead halide coordination polymer with strong layer corrugation and high chemical robustness

“…1.5% of (N-MEDA)[PbBr 2.8 Cl 1.2 ], 16 9% of (EDBE)[PbBr 4 ], 40 Given the efficient broadband emission from TJU-19, we sought to investigate its long-term stability under various chemical conditions. First, the high crystallinity and phase purity have been largely retained after the incubation of TJU-19 in a variety of aqueous solutions over a wide range of pH values (3)(4)(5)(6)(7)(8)(9)(10)(11) and in a variety of organic solvents including high-polar protic solvents, evidenced by PXRD and negligible loss in mass balance (Fig. 3a, d and e).…”

“…Organolead halide hybrids are an emerging class of crystalline materials with excellent photophysical properties, therefore showing optoelectronic applications in light-emitting diodes, [1][2][3][4][5] photovoltaic solar cells, [6][7][8][9] and photodetectors. [10][11][12] Among them, a selected group of organolead halide perovskites have attracted widespread attention for their unique emissions from self-trapped excitons (STEs), which play the role of defective excited states to afford a large Stokes shift and broadband emission. 13 Mechanistic studies indicate that the formation of STEs originates from the structural distortion of lead halide sublattices, especially the out-of-plane distortion of halide species.…”

Enhanced stability and tunable photoluminescence in Mn2+-doped one-dimensional hybrid lead halide perovskites for high-performance white light emitting diodes

“…Lead trihalide-based three-dimensional (3D) perovskite materials (APbX 3 , A = Cs + , methylammonium; X = Cl, Br, I) have garnered signicant research interest for various optoelectronic devices, including high-efficiency solar cells, color-tunable and narrow linewidth light-emitting diodes (LEDs), lasers, and photodetectors. [1][2][3][4][5][6][7][8] These materials represent a new paradigm for renewable energy sources due to their exceptional charge carrier mobilities, low density of midgap trap states, and defecttolerant nature. Furthermore, 3D APbX 3 -based materials offer potential applications in solid-state lighting and display technologies, owing to their attractive optical properties, such as high PLQY, tunable bandgaps, emission wavelengths spanning the entire visible spectrum, narrow linewidths and rapid radiation decay rates.…”