Ambipolar Organic Field Effect Transistor Memory Based on H-Type Fluorene-Based Small Molecule

A small organic molecule 3Ph-TrH with a rigid structure was designed with p-bridge thienyl and fluorenyl groups as hole trapping sites and the fluorenyl and phenyl units as electron trapping sites according to steric hindrance. Then, the floating gate type organic field-effect transistor (OFET) memories based on this small organic molecule through solution processing were fabricated. The experimental results show that there is a hole storage window of 31.2 V and an electron storage window of 11.6 V in this device, exhibiting ambipolar charge storage based on a single small molecule material. To improve the stability of the device, a floating-gate OFET memory based on 3Ph-TrH with polystyrene (PS)-doped film was further prepared. The test results show that the device is equipped with better device stability and tolerance than those based on 3Ph-TrH as a single-component charge trapping layer. After 10000 s of retention times test, ON/OFF current ratio of the device can still be maintained at 1.1x10(3), only reduced by an order of magnitude. This work can provide an idea for the preparation of a new type of OFET memory with ambipolar storage.