High Performance Organic Electronic Devices Based on a Green Hybrid Dielectric

As the cost of electronics decreases, the demand for short-term and single-use applications, such as smart packaging, increases. Consequently, there is significant need for electronically active biodegradable materials to reduce the environmental impact of disposable electronic devices. A bilayer dielectric is developed based on environmentally friendly, low-cost solution-processable polymers, fabricated by thermally crosslinking a toluene diisocyanate-terminated polycaprolactone (TPCL) layer with the hydroxyl groups of a poly(vinyl alcohol)/cellulose nanocrystal (CNC) blended dielectric (PVA_C). Metal–insulator–metal (MIM) capacitors are fabricated and characterized under ambient and humid conditions. The incorporation of a TPCL layer in the bilayer dielectric results in a large reduction in moisture sensitivity when compared to neat PVA_C without significantly altering the dielectric constant. When utilized as a dielectric in organic thin-film transistors (OTFTs), the transistors prepared with the PVA_C/TPCL dielectric have greater on/off ratios and hole mobilities, with reduced hysteresis compared to devices fabricated with PVA_C. Furthermore, the fabricated OTFTs function at operating voltages six times lower when compared against a traditional silicon dioxide (SiO₂) dielectric. The facile processing, combined with superior device performance, makes this green bilayer dielectric a promising candidate material for biodegradable disposable electronic applications.