Transparent polymer nanoheterostructure films for flexible low-power organic transistors with high mobility, decent photostability, and ultralong-term air stability

Organic field-effect transistors (OFETs) are promising candidates for flexible electronic devices, but their instability remains a huge challenge that should be solved for practical applications. It is very difficult to achieve high-performance energy-efficient OFETs with good photostability and ultralong-term air stability. Here, a novel type of transparent and stable polymer films comprising p-type nanofibrous semiconductor and insulating polystyrene is developed, forming the nanoscale cross-interconnected heterostructures. The nanoheterostructure films as channel layers enable flexible low-power OFETs to achieve highly improved mobilities up to 6.78 cm2 V−1 s−1 at a low-operating voltage of −0.5 V despite the small semiconductor content, and the substantial amount of inert insulators can effectively prevent external factors such as light, moisture, and oxygen from interfering with the semiconductor layer. As results, the flexible OFETs using these nanoheterostructure films show slight performance changes under different light illuminations even by three laser beams, and their unencapsulated devices retain excellent performance even after over 450 days of ultralong-term and high-humidity air exposure. These findings demonstrate that nanoscale heterostructure films of polymer semiconductors and insulators constitute a simple yet efficient strategy for improving the OFET stability, which holds great promise for developing high-performance durable and energy-saving devices in flexible and transparent electronics.