Organic nonvolatile memory devices utilizing intrinsic charge trapping phenomena in an n type polymer semiconductor
Abstract Charge trapping is an undesirable phenomenon and a common challenge in the operation of n channel organic field effect transistors. Herein, we exploit charge trapping in an n type semiconducting poly (naphthalene diimide alt biselenophene) (PNDIBS) as the key operational mechanism to develop high performance, nonvolatile, electronic memory devices. The PNDIBS based field effect transistor memory devices were programmed at 60 V and they showed excellent charge trapping and de trapping characteristics, which could be cycled more than 200 times with a current ratio of 103 between the two binary states. Programmed data could be retained for 103 s with a memory window of 28 V. This is a record performance for n channel organic transistor with inherent charge trapping capability without using external charge trapping agents. However, the memory device performance was greatly reduced, as expected, when the n type polymer semiconductor was end capped with phenyl groups to reduce the trap density. These results show that the trap density of n type semiconducting polymers could be engineered to control the inherent charge trapping capability and device performance for developing high performance low cost memory devices.