Robust switching characteristics of CdSe/ZnS quantum dot non-volatile memory devices

Abstract

In this paper we report Al/CdSe–ZnS core–shell quantum dot/AlO_x/CdSe–ZnS core–shell quantum dot/ITO based non-volatile resistive memory devices with an ON/OFF ratio of ∼1000. The facile solution processed device exhibited excellent endurance characteristics for 200 000 switching cycles. Retention tests showed good stability for over 20 000 s and the devices are reproducible. A memory operating mechanism is proposed based on charge trapping–detrapping in core–shell quantum dots with AlO_x acting as a barrier leading to Coulomb blockade. I–V characteristics of a three terminal device fabricated with the additional terminal wired-out from the middle AlO_x layer supports the proposed charge trapping mechanism.