Electroluminescence occurs via recombination reactions between electrons and holes, but these processes have not been directly evaluated. Here, we explore the operation dynamics of ionic liquid-based light-emitting electrochemical cells (LECs) with stable electroluminescence by multi-timescale spectroscopic measurements synchronized with the device operation. Bias-modulation spectroscopy, measuring spectral responses to modulated biases, reveals the bias-dependent behavior of p-doped layers varying from growth to saturation and to recession. The operation dynamics of the LEC is directly visualized by time-resolved bias-modulation spectra, revealing the following findings. Electron injection occurs more slowly than hole injection, causing delay of electroluminescence with respect to the p-doping. N-doping proceeds as the well-grown p-doped layer recedes, which occur while the electroluminescence intensity remains constant. With the growth of n-doped layer, hole injection is reduced due to charge balance, leading to hole-accumulation on the anode, after which LEC operation reaches equilibrium. These spectroscopic techniques are widely applicable to explore the dynamics of electroluminescence-devices.
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http://dx.doi.org/10.1038/s41467-023-36472-6 | DOI Listing |
Molecules
November 2024
Department of Chemical Engineering, National Chung Hsing University, Taichung 40227, Taiwan.
In this study, a three-dimensional (3D) interconnected porous Ni/SiC skeleton (3D Ni/SiC) was synthesized by binder-free hydrogen bubble template-assisted electrodeposition in an electrolyte containing Ni ions and SiC nanopowders. This 3D Ni/SiC skeleton served as a substrate for directly synthesizing nickel-cobalt layered double hydroxide (LDH) nanosheets via electrodeposition, allowing the formation of a nickel-cobalt LDH nanosheet-decorated 3D Ni/SiC skeleton (NiCo@3D Ni/SiC). The multiscale hierarchical structure of NiCo@3D Ni/SiC was attributed to the synergistic interaction between the pseudocapacitor (3D Ni skeleton and Ni-Co LDH) and electrochemical double-layer capacitor (SiC nanopowders).
View Article and Find Full Text PDFChem Sci
December 2024
MOE Key Laboratory for UV Light-Emitting Materials and Technology, Northeast Normal University Changchun Jilin 130024 China
Nano Converg
November 2024
Radiation Laboratory, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA.
Lead halide perovskites have emerged as a new class of semiconductor materials with exceptional optoelectronic properties, sparking significant research interest in photovoltaics and light-emitting diodes. However, achieving long-term operational stability remains a critical hurdle. The soft, ionic nature of the halide perovskite lattice renders them vulnerable to various instabilities.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
NANOTECH Centre, Ural Federal University, Mira Str., 19, 620002 Ekaterinburg, Russia.
Nanotubular hafnia arrays hold significant promise for advanced opto- and nanoelectronic applications. However, the known studies concern mostly the luminescent properties of doped HfO-based nanostructures, while the optical properties of nominally pure hafnia with optically active centers of intrinsic origin are far from being sufficiently investigated. In this work, for the first time we have conducted research on the wide-range temperature effects in the photoluminescence processes of anion-defective hafnia nanotubes with an amorphous and monoclinic structure, synthesized by the electrochemical oxidation method.
View Article and Find Full Text PDFChem Soc Rev
January 2025
Technical University of Munich, Campus Straubing for Biotechnology and Sustainability, Chair of Biogenic Functional Materials, Schulgasse 22, Straubing 94315, Germany.
The development of novel, efficient and cost-effective emitters for solid-state lighting devices (SSLDs) is ubiquitous to meet the increasingly demanding needs of advanced lighting technologies. In this context, the emergence of thermally activated delayed fluorescence (TADF) materials has stunned the photonics community. In particular, inorganic TADF material-based compounds can be engineered by chemical modification of the coordinated ligands and the type of metal centre, allowing control of their ultimate photo-/electroluminescence properties, while providing a viable emitter platform for enhancing the efficiency of state-of-the-art organic light-emitting diodes (OLEDs) and light-emitting electrochemical cells (LECs).
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