Ultrathin Free-Substrate n-Type PTCDI-C13 Transistors With Bilayer Polymer Dielectrics

Polymethyl methacrylate (PMMA)/poly(viny-lalcohol) (PVA) bilayer polymer dielectrics were used to fabricate ultra-thin free-substrate n-type PTCDI-C13 organic thin-film transistors. PVA can help peel the entire device from the supporting layer, while PMMA improves the performance of the n-type OTFTs. As a result, we were able to achieve a current ON/OFF ratio exceeding 10⁷ for an ultra-thin (~590 nm) substrate-free PTCDI-C13 OTFT. The electron mobility achieved as high as 0.54 cm² V^-1 s^-1. These n-type OTFTs can successfully adhere to a 3-D curved surface with nearly unaltered mobility and current ON/OFF ratio and a strong resistance to crumpling. These results show that ultrathin flexible n-channel OTFTs have promising potential for applications in flexible and conformal electronic devices.