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The key to utilizing quantum dots (QDs) as lasing media is to effectively reduce non-radiative processes, such as Auger recombination and surface trapping. A robust strategy to craft a set of CdSe/Cd1− xZn xSe1− yS y/ZnS core/graded shell-shell QDs with suppressed re-absorption, reduced Auger recombination rate, and tunable Stokes shift is presented. In sharp contrast to conventional CdSe/ZnS QDs, which have a large energy level mismatch between CdSe and ZnS and thus show strong re-absorption and a constrained Stokes shift, the as-synthesized CdSe/Cd1− xZn xSe1− yS y/ZnS QDs exhibited the suppressed re-absorption of CdSe core and tunable Stokes shift as a direct consequence of the delocalization of the electron wavefunction over the entire QD. Such Stokes shift-engineered QDs with suppressed re-absorption may represent an important class of building blocks for use in lasers, light emitting diodes, solar concentrators, and parity-time symmetry materials and devices. [ABSTRACT FROM AUTHOR]

A facile one‐step fabrication of large‐area multicolored emissive photopatterns in mixed quantum dot‐polymer films is demonstrated. This is in sharp contrast to the current photopatterning approaches that utilize only a single quantum dot (QD) component for single‐color patterns. Strategies are presented that allow for either selective or collective modification of specific predetermined photoluminescent peaks of green and red QDs during photopattern development. These strategies yield novel patterns and allow for unprecedented control over how the color contrast of the photopattern evolves with continuous light illumination. These results clearly show that the evolution of the emission spectra of a multicolor mixed QD‐polymer film can be readily tailored during pattern development, either by careful selection of the excitation wavelength or through combinations of controllably unstable and stable QDs with different recovery rates. Notably, these strategies are simple, fast, and robust, yielding high‐resolution microscopic patterns over large areas (up to fractions of a cm2). Furthermore, the flexibility and capabilities of these strategies greatly expand the potential applications of multicolor emissive photopatterns, particularly in the areas of sensing, imaging, and lasing systems where it is important to exert delicate control over the intensity of selected colors within specific spatial regions. [ABSTRACT FROM AUTHOR]

Since their inception, quantum dots have proven to be advantageous for light management applications due to their high brightness and well‐controlled absorption, scattering, and emission properties. As quantum dots become commercially available at large scale, the need for robust, stable, and flexible optical components continues to drive the development of robust and flexible quantum dot composite materials. In this review, after a thorough introduction to quantum dots, discussion delves into methods for fabricating quantum dot loaded composite optical elements such as thin films, microfabricated patterns, and microstructures. The importance of surface chemistry and ligand engineering, host matrixes, wet processing, and unique patterning methodologies is presented by considering photostability, aggregation, and phase separation of quantum dots in corresponding composites. With regard to prospective optical applications of quantum dot materials, emphasis is placed on light emitting and guiding composite materials for lasing applications, specifically whispering gallery mode‐based photonic microsystems. These developments will enable novel flexible, portable, and miniaturized optoelectronic devices such as light‐emitting diodes, flexible pixelated displays, solar cells, large‐area microwaveguides, omnidirectional micromirrors, optical metasurfaces, and directional microlasers. Herein the state of the art of quantum dot composite materials is described, with particular interest paid to light emitting and guiding technologies. Great attention is paid to micropatterning, focusing on the importance of surface chemistry and ligand engineering, host matrixes, and wet processing to achieve optimal photostability, aggregation, and phase separation of quantum dots in corresponding patterns and resulting devices. [ABSTRACT FROM AUTHOR]