Operating mechanisms of highly-reproducible write-once-read-many-times memory devices based on graphene quantum dot:poly(methyl silsesquioxane) nanocomposites

摘要

Resistive switching memory devices were fabricated utilizing graphene quantum dot (GQD): poly(methyl silsesquioxane) (PMSSQ) hybrid nanocomposites. Current-voltage curves for the Al/ GQD:PMSSQ/indium-tin-oxide devices at room temperature showed write-once-read-many-times memory (WORM) characteristics with an ON/OFF ratio of as large as 10~6 due to the homogeneous dispersion of the GQDs in the PMSSQ matrix. The WORM devices maintained retention times larger than 2 × 10~4 s under ambient conditions. The devices showed high device-to-device repro-ducibility with threshold-voltage distributions between 3 and 5 V. The ON state currents remained between 10~(-6) and 10~(-3) A, and the OFF state currents maintained between 10~(-12) and 10~(-9) A. The operating mechanisms concerning the interaction between the GQDs and the PMSSQ matrix for the resistive-switch phenomenon were analyzed on the basis of the Ⅰ-Ⅴ results and with the aid of the energy band diagram.