Local fluorescence enhancement of perovskite quantum dots glass via picosecond laser micromachining

Perovskite quantum dot (PQD) glass offers an effective approach to improving the environmental stability of quantum dots while maintaining their favorable optical properties. However, conventional melt quenching and annealing methods yield homogeneous PQD distributions, which lack the spatial controllability required for integrated photonic applications. In this work, CsPbBr₃ PQD-embedded borosilicate glass was prepared via high-temperature melting and heat treatment. Picosecond laser direct writing was then employed to induce localized "secondary annealing" through thermal effects, significantly enhancing the crystallinity and photoluminescence intensity in the irradiated regions. Under UV excitation, the treated areas exhibited markedly stronger green emission, with the photoluminescence quantum yield (PLQY) increasing from 14% to 22%, while allowing precise spatial control of the luminescent patterns. In contrast to femtosecond laser-based in situ synthesis of PQDs in glass, this method performs localized thermal repair on preformed PQD glass, optimizing existing quantum dots rather than creating new ones. This work provides a new, to the best of our knowledge, strategy for spatially selective optical tuning of PQD glass toward integrated micro-photonic devices.