One material with two functions could lead to faster memory

Researchers use perovskite to develop a memory device readable through both electrical and optical methods

A fast-switching, all-inorganic CsPbBr3 perovskite quantum dot device with simultaneous resistance change memory (RRAM) and luminescent electrochemical cell (LEC) functionality has been developed. This new device with multiple functions can signal whether the memory is in a "write" or "erase" state with different emission colors by carefully controlling the flow of ions through modulation of bias polarity. This new idea of electrically switchable light-emitting memory devices by simply connecting all perovskite elements in series is expected to show new possibilities in the field of optoelectronics, as it aims to exploit the synergy between the optical and electrical properties of perovskite materials.

The University has also issued a press release.

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 optoelectronic device performance. Here, we show that the functionality of a single Ag/CsPbBr3/ITO device can be actively switched on a sub-millisecond scale from a resistive random-access memory (RRAM) to a light-emitting electrochemical cell (LEC), or vice versa, by simply modulating its bias polarity. We then realize for the first time a fast, all-perovskite light-emitting memory (LEM) operating at 5 kHz by pairing such two identical devices in series, in which one functions as an RRAM to electrically read the encoded data while the other simultaneously as an LEC for a parallel, non-contact optical reading. We further show that the digital status of the LEM can be perceived in real time from its emission color. Our work opens up a completely new horizon for more advanced all-inorganic perovskite optoelectronic technologies.