Stretchable PDMS Encapsulation via SiO2 Doping and Atomic Layer Infiltration for Flexible Displays

Abstract Stretchable encapsulation plays a crucial role in expanding the applications of flexible electronics, particularly the large‐area flexible displays. In this work, polydimethylsiloxane (PDMS) hybrid films with high stretchability, excellent transparency, and good barrier property are achieved by a simple process of SiO 2 doping and atomic layer infiltration (ALI). The doped SiO 2 improves the mechanical property and serves as reaction sites for the Al 2 O 3 infiltration. A clear “nucleation‐filling‐coating” mechanism of Al 2 O 3 ALI is proposed and elaborated in detail by in situ quartz crystal microbalance. The optimized PDMS hybrid films exhibit a relatively low water vapor transmission rate (WVTR) value of 1.81 × 10 −3 g m −2 day −1 and excellent mechanical reliability, where after 1000 cycles of the fatigue stretching test at 1% tensile strain the WVTR only slightly increases to 2.01 × 10 −3 g m −2 day −1 . Furthermore, the patterned quantum dots encapsulated with PDMS hybrid films still retain more than 50% photoluminescent intensity even after the stretching and storage in deionized water for 2400 h, which is ≈80 times longer than the pristine ones. Therefore, the proposed combined method of SiO 2 doping and ALI modification has great and practical implications for stretchable encapsulations for future flexible electronics.