Ag-CsPbI₃ nanocomposite structure in glasses boosts photoluminescence for efficient light emitting diodes

Nanocomposite structures based on perovskite nanocrystals (NCs) and metal nanostructures within transparent monolithic media hold promise for a wide range of applications in optoelectronics. However, the microstructure of such nanocomposites and the reason for enhanced emissions remain incompletely understood. In this work, we present the successful creation of Ag-CsPbI₃ nanocomposite within a highly transparent borosilicate glass (Ag-CsPbI₃ NCs@glass). We reveal that Ag and CsPbI₃ NCs form after thermal treatment of the glass, either in the form of Ag-CsPbI₃ heterostructures or of separate Ag and CsPbI₃ NCs. Based on combined characterization of Mott-Schottky and steady-state photoluminescence (PL) of the products, we attribute the enhanced PL in the nanocomposite of Ag-CsPbI₃ to the regulation of CsPbI₃ lattice by Ag ions and/or the plasmonic effect of Ag NCs. Temperature-dependent time-resolved PL decay measurements suggest that Ag NCs could play an important role in the relaxation process of excited carriers by increasing the radiative recombination. Moreover, the Ag-CsPbI₃ nanocomposite structure within the glass matrix curtails PL quenching caused by water molecules and high temperature. Using the Ag-CsPbI₃ nanocomposite, we achieve high-performance white light-emitting diodes with a color rendering index of 83.9 and luminous efficiency of 58.07 lmW⁻¹. This work elucidates the underlying mechanism on the enhanced PL in nanocomposites containing perovskite NCs and metal nanostructures, and aids in the rational design of glass-based perovskite nanocomposites for a diversity of optoelectronic applications. © 2024 Elsevier B.V.