Organic Field-Effect Transistor/Memory Devices with Pentacene/Polydiacetylene Composite Film As Active Channel Material: A Morphology Dependence Study

Composite films of pentacene and poly(10,12-pentacosadiynoic acid) were prepared and used as the active channel material in a top-contact, bottom-gate field-effect transistor. The transistors exhibited high field-effect mobility as well as large I-V hysteresis as a function of gate bias history. The polydiacetylenic moieties incorporated in the pentacene film served as charge storage vehicles, which affected the threshold voltage shifts and created the electric bistability needed in a memory device. The memory window, response, and retention highly depend on the morphology of the polydiacetylene film buried under. Detailed film structure analyses and correlation with the transistor/memory property are provided.