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

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.