All-inorganic perovskite quantum dot light-emitting memories

• Published in: Nature communications Vol. 12; no. 1; pp. 4460 - 12
• Main Authors: Yen, Meng-Cheng, Lee, Chia-Jung, Liu, Kang-Hsiang, Peng, Yi, Leng, Junfu, Chang, Tzu-Hsuan, Chang, Chun-Chieh, Tamada, Kaoru, Lee, Ya-Ju
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.07.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1005/1007; 639/301/357/995; 639/624/399/1017; 639/925/357/995; Electric contacts; Electric fields; Electrochemical cells; Electrochemistry; Humanities and Social Sciences; Ion migration; Light emission; multidisciplinary; Optical properties; Optoelectronic devices; Perovskites; Polarity; Quantum dots; Random access memory; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-24762-w

Field-induced ionic motions in all-inorganic CsPbBr 3 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/CsPbBr 3 /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. Electric field induced ion migration is a well-known phenomenon in perovskite, but the consequences are notorious, and thus needs to be prevented. Here, on the other hand, the authors cleverly manipulate this event for realising resistive random-access memory and light-emitting electrochemical cell in one device based on CsPbBr 3 quantum dots.