Flexible, Stretchable, and Luminescent Hydrogels Based on a Polydimethylsiloxane-Coated CsPbBr₃ Nanostructure for Elastomers

Cesium lead halide perovskite nanocrystals (PNCs) haveattractedgreat attention in optoelectronic devices due to their excellent opticalproperties, such as tunable emission wavelengths, long carrier lifetime,and narrow full width at half-maximum (fwhm). However, the poor stabilityof PNCs in water or humid environments greatly limits their wide-spreadingapplications. It is challenging to prepare PNCs with long-term stabilityin water. Herein, we successfully prepared CsPbBr3@PDMSmicrospheres by using the emulsification method. Due to the protectionof the PDMS layer, the CsPbBr3@PDMS microspheres exhibitgood optical properties and stability in water, acid, and alkali solutions.In addition, to expand the application of CsPbBr3 NCs inflexible optical devices and wearable devices, we first prepared stretchable,stable, and photoluminescent hydrogel with a CsPbBr3@PDMSmicrosphere (hydrogel/CsPbBr3@PDMS) by using the emulsificationmethod. The hydrogel/CsPbBr3@PDMS elastomer exhibits goodstability and stretchability. Furthermore, the hydrogel/CsPbBr3@PDMS elastomer retains bright green emission and stabilityunder different mechanical deformations. This work provides a methodto improve the CsPbBr3 PNCs with high stability by emulsification,which could also expand the applications of PNCs in underwater display,wearable, and flexible optoelectronic devices.