N, S-codoped cross-linked polymers for low switch voltage and high thermal stable nonvolatile memory

Heteroatoms doping is an effective strategy to boost polymer materials with desirable functions for advanced electronics and optoelectronics. Herein, two N or S heteroatoms were employed to construct large-area two-dimensional N, S-codoped conjugated microporous polymer (N, S-CMP) film for nonvolatile memory. The CMP films exhibited excellent thermal stability due to the cross-linked structure. The vertical diode with the sandwich structure of ITO/N, S-CMP/Al showed rewritable flash memory function, with a low switch voltage of 0.9 V, a high ON/OFF ratio of 1.3 × 10² and long retention time of up to 8 × 10³ s. The flash behavior is probably attributed to the strongly coordinating S atoms with metal ions, which can lead the reproducible metal filament formation process. Impressively, even after annealing at 200 °C, the device also showed flash performance, indicating its excellent thermal stability. Our work provides a promising strategy to prepare CMPs for highly stable polymer memory.