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Abstract In recent years, quantum dot light-emitting diodes (QLEDs) have achieved record-high performance, driven by rapid advances in active materials and device engineering. However, fabrication remains a significant barrier for new researchers entering the field, and variability in measurement techniques complicates direct comparison of device performance. Here, we establish a standardized and reproducible protocol for QLED fabrication and characterization, designed to lower the technical threshold, improve experimental reliability, and ensure accurate performance assessment. The protocol was independently validated by researchers with different levels of experience. In addition, we provide detailed troubleshooting guidelines and identify key sources of variability in QLED devices. By integrating electron transport material synthesis, optimized thin-film processing, and standardized device characterization procedures, this protocol ensures consistent device performance and promotes broader adoption of QLED technology across the research community. 

Magic-sized clusters are atomically precise nanoparticles that eliminate heterogeneous broadening, thereby enabling narrow ensemble emission. However, the discrete structural stability that causes only certain-sized clusters to exist also inherently disallows continuous optoelectronic tunability. New strategies are required to allow magic-sized clusters to continuously cover regions of the visible spectrum. Herein, we investigate the atomic structures of two oleate-ligated Cd3P2-450 and Cd3As2-525 clusters and conclude that they are structurally homologous based on pair distribution function analysis. The structural similarities between Cd3P2-450 and Cd3As2-525 allow alloying of P and As in these magic-sized clusters without perturbing the structure or the impressive optical properties. Ligand exchange for phosphinate then produces Cd3P2–xAsx magic-sized clusters with continuously tunable, narrow, and bright emission from blue (λmax = 469 nm) to green (λmax = 550 nm). 

The atomic precision of magic-sized clusters offers a route toward narrow emission by eliminating heterogeneous broadening. Herein, we report ultranarrow 467 nm blue emission from cadmium phosphide clusters with a 96 meV line width and as high as 26% photoluminescence quantum yield (PLQY) enabled by tightly bound, bidentate phosphinate ligands. They are obtained through postsynthetic ligand exchange from oleate-capped clusters. The phosphinate maintains the bidentate coordination motif, which does not disturb the metastability of the material but does induce a change in the surface dipole, causing a bathochromic shift in the emission from 457 to 467 nm, which is an optimal wavelength for blue emission. We find that the structure of the ligand tail can heavily influence PLQY and other aspects of the charge carrier dynamics. The ligand exchange protocol can be applied to the related cadmium arsenide clusters, resulting in a narrow 550 nm green emission with a 9% PLQY. 

Semiconductor nanomaterials with complex compositions have emerged as next-generation materials for applications in catalysis, energy storage, and sensing. Despite achieving high-quality doped II–VI and III–V semiconductor nanocrystals in specific cases, a general approach to compositional control is lacking. Leveraging the metastability of semiconductor magic-sized clusters (MSCs), we demonstrate a general approach to sequential cation exchange under mild conditions. The sequential exchange begins with In37P20(O2CC13H27)51 MSCs and proceeds through a copper-doped intermediate to achieve Mn-, Co-, Fe-, and Mo-doped clusters at ambient temperature. The resulting products are spectroscopically and structurally characterized to track changes in absorbance, composition, and size. Moreover, we use these doped clusters as seeds for the growth of doped InP nanocrystals, and in doing so, we find that the cluster dopant can be preserved throughout the growth process, resulting in different degrees of incorporation depending on the dopant identity. Finally, the addition of tributylphosphine and mild heating were employed as postsynthetic strategies to remove Cu impurities in the final doped nanocrystals. This mild approach for transition metal doping of MSCs through a sequential cation exchange reaction offers a versatile route toward doped and multicomponent nanocrystals. 

Exploiting the ability of a solid-binding elastin-like peptide to micellize, we mineralize monodisperse silica nanoparticles whosepositivesurface charge enables one-step electrostatic assembly of various mono- and bi-material superstructures.