East China University of Science and Technology, China
Title: Polymer covalently modified graphene for nonvolatile rewritable memory
Yu Chen is a full Professor of East China University of Science and Technology in Shanghai. He received his PhD in Organic Chemistry at Fudan University in 1996. In 2000, he joined Prof. Dr. Michael Hanack's group at the University of Tuebingen as an Alexander von Humboldt research fellow. At the end of October 2002, he moved to the University of Washington, and worked with Prof. Dr. Alex K.Y. Jen as a Research Associate. In 2004, he joined Professor Dr. Osamu Ito’s group at the Tohoku University as a research scientist. He has published more than 160 papers in the peer-review journals.
The data storage performance, stability and reliability of the graphene memories have advanced significantly towards practical information storage applications. A number of essential strategies can be employed to control and optimize the switching characteristics of graphene memories for practical information storage applications. Covalent functionalization of graphene oxide (GO) or, reduced graphene oxide (RGO) with electroactive polymers is an effective and versatile approach to tuning the electronic properties of graphene. The facile engineering of GO/RGO energy bandgap through polymer functionalization also provides an alternative route to supplement the lithographical patterning of graphene sheets into low dimensional nanostructures and chemical modification of graphene nanoribbons. By using the “grafting to” or “grafting from” method, we have synthesized a new series of soluble polymer-covalently grafted GO/RGO functional materials. Bistable electrical switching effects and non-volatile rewritable memory effects were observed in the ITO/graphene-based polymer/Al sandwiched devices, with small switch-on voltage of about -1~-2 V and the ON/OFF current ratio of more than 103. The non-volatile nature of the ON state and the ability to write, read and erase the electrical states fulfilled the functionality of a rewritable memory. Both the ON and OFF states were stable under a constant voltage stress for more than 104 s and survived up to 108. read cycles at a read voltage of -1.0 V.