Iridium(iii) complex-containing non-conjugated polymers for non-volatile memory induced by switchable through-space charge transfer

Abstract

Organic memory devices have recently attracted considerable interest to combat the increasing demands of data storage. Herein, taking advantage of the electron-deficient nature of iridium(III) complexes and the flexible polymer skeleton of non-conjugated polymers, a series of novel non-conjugated iridium(III) complex-containing polymers P2–P5 with non-volatile memory properties, and the corresponding model polymer P1, were rationally designed and synthesized. The memory effect of P1 is a static random-access memory type, while that of the polymers containing iridium(III) complexes are flash types. The ON/OFF current ratio of the devices based on P3 is as high as 10³ and the device has good stability. It exhibits a long retention time of 10⁴ s and both ON and OFF states, which survive up to more than 10⁵ read cycles. The introduction of an iridium(III) complex contributes to the charge-transfer states from carbazole moieties to the iridium(III) complex, which also improves the crystallinity of polymers and realizes electrical bistability.