All-inorganic perovskite quantum dot light-emitting memories

Abstract

Field-induced ionic motions in all-inorganic CsPbBr3 perovskite quantum dots (QDs) strongly dictate not only their electro-optical characteristics but also the ultimate device performance of the CsPbBr3 optoelectronics. Novel device concepts with multiple functionalities can as a result be achieved based on CsPbBr3 by carefully controlling the ionic flow under different bias conditions. Here, we show that by manipulating the ion migrations in two nominally identical, series-connected Ag/CsPbBr3/ITO devices, one device can operate as a resistive random-access memory (RRAM) while the other simultaneously as a light-emitting electrochemical cell (LEC), or vice versa, simply through the polarity switching of the external bias across the entire structure. We further show that this electrically switchable, series-connected perovskite memories and light emitters can be employed as a novel all-perovskite light-emitting memory (LEM) device for simultaneous electronic and optical reading of the encoded information in communication and computation applications. We present a physical picture that clearly depicts the movements of each ionic species and their reduction or oxidation processes in the perovskite LEM responsible for the observed electronic and optical characteristics. The demonstrated bifunctionality of the simple metal-perovskite-metal structures and the novel device concept derived from their creative synergy opens up a completely new horizon for more advanced all-inorganic perovskite optoelectronics with novel functionalities.