Photoelectronic memory based on nitride multiple quantum wells and the hybrid of graphene nanoflakes and a-IGZO film

Opt Express. 2020 Apr 27;28(9):13542-13552. doi: 10.1364/OE.374548.

Abstract

Optical memories are vitally important for the future development of high speed and low cost information technologies. Current optical memory devices still suffer from difficulties such as scaling-down of size, short-life expectancy, and non-volatility without the control of a gate electrode. To resolve these obstacles, a robust photoelectronic memory device is designed and demonstrated based on the integration of amorphous InGaZnO (a-IGZO), GNSs, and nitride multiple-quantum-wells light-emitting diode (MQWs LED). Utilizing the inherent nature of the band alignment between a-IGZO and graphene nanosheets (GNSs), electrons can transfer from a-IGZO to GNSs causing a persistent photoconductivity (PPC). With the long-lasting lifetime of PPC, the signal can be written optically and the encoded signal can be read both electrically and optically. The read and write processes reveal little current degradation for more than 10,000 sec, even repeated for more than hundred times. The device can convert invisible information to visible signal, and the encoded information can be simply erased under a reversed bias without a gate electrode. In addition, the memory device possesses a simple vertically stacked structure for 3D integration, and it is compatible with established technologies.