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Abstract Structural deformation modifies the bandgap, exciton fine structure and phonon energy of semiconductors, providing an additional knob to control their optical properties. The impact can be exploited in colloidal semiconductor quantum dots (QDs), wherein structural stresses can be imposed in three dimensions while defect formation is suppressed by controlling surface growth kinetics. Yet, the control over the structural deformation of QDs free from optically active defects has not been reached. Here, we demonstrate strain-graded CdSe-ZnSe core-shell QDs with compositionally abrupt interface by the coherent pseudomorphic heteroepitaxy. Resulting QDs tolerate mutual elastic deformation of varying magnitudes at the interface with high structural fidelity, allowing for spectrally stable and pure emission of photons at accelerated rates with near unity luminescence efficiency. We capitalize on the asymmetric strain effect together with the quantum confinement effect to expand emission envelope of QDs spanning the entire visible region and exemplify their use in photonic applications.

Gallium ion incorporation into silver indium gallium sulfide nanocrystals is investigated by various methods, including photoluminescence (PL) and X-ray photoelectron spectroscopy. The ZnS shell-growth enhances a PL quantum yield of up to 16%, with which the quantum dot light-emitting diode was successfully fabricated. [ABSTRACT FROM AUTHOR]

Quantum dot light-emitting diodes (QLEDs) are intensively developed in the display industry owing to their outstanding optoelectronic properties. However, their limited stability significantly limits broader display applications. Recently, a few studies have highlighted a phenomenon known as positive aging, in which post-treatment with a UV-curable acidic resin enhances both the lifetime and efficiency of QLEDs, thus offering a promising approach for overcoming limited lifetimes. Nonetheless, these treatments involve high-viscosity acidic resins, necessitating simpler processes for practical commercialization. In this study, a comparable performance-enhancing effect was verified by simply premixing the most abundant component of acidic resin, 2-hydroxyethyl methacrylate (HEMA), with ZnMgO (ZMO) to create an electron transporting layer. The QLED developed in this study, which incorporates HEMA-premixed ZMO, demonstrated 1.4- and 2.1-fold improvements in external quantum efficiency and half-lifetime, respectively. Comprehensive analyses of both the thin films and devices were conducted to elucidate the reasons behind these enhancements. [ABSTRACT FROM AUTHOR]