A multilayer barrier structure composed of silicon nitride, silicon oxide, and encapsulated parylene on a polycarbonate substrate has been investigated for flexible electronic applications. The organic buffer is commonly used as the smoothing, strengthening and defect-decoupling layer. However, a lateral leakage problem was observed in the organic interlayer, and resulted in increased permeation and poor adhesion between organic and inorganic layers. It was found that an encapsulated, thermal-treated parylene interlayer can be used to efficiently reduce the water vapor and oxygen permeation. After 75 d, the water vapor transmission rate (WVTR) can reach 2.5 × 10-7 (g · m-2) d-1, as calculated by the calcium test. After being flexed for 5 000 times, the WVTR value almost keeps around 2.1 × 10-6 (g · m-2) d-1. The performance of the proposed multilayer barrier structure has a high potential for flexible solar cell and organic light-emitting diode applications.
- Flexible electronics
- Water-vapor permeability