Ultrafast nonvolatile optoelectronic memory enabled by conformal nanointerfaces

Abstract

In the field of ultrafast optoelectronic memory technologies, organic field-effect transistor (OFET) memory has attracted considerable attention due to its multifunctionality, tunability, and low power consumption. Among its components, the charge-trapping layer plays a critical role in nonvolatile OFET memory design. Proper modulation of this layer can enhance memory performance. To further enhance the programming speed and stability of the device, it is essential to construct large-scale multifunctional nanostructures with tunable nanostructure dimensions within the charge-trapping layer. Herein, blending poly(9-vinylcarbazole) and poly(9,9-dioctylfluorene-2,7-diyl) with distinct chain lengths induces phase separation due to their surface energy difference, enabling the formation of a densely distributed, large-scale nanopillar array with tunable dimensions. A conformal interface with a semiconductor layer is subsequently achieved. This precisely controlled interface enhances trap-assisted tunneling, accelerating charge injection and facilitating the Fowler–Nordheim tunneling process. The devices demonstrate ultrafast nonvolatile memory performance, including a 50 μs programming speed and sustained retention exceeding 22 000 s. Architectural periodicity in patterned polymeric nanostructures has been demonstrated to govern charge-trapping efficacy. Conductive atomic force microscopy reveals the operational mechanisms by which the ordered interfaces fundamentally regulate the carrier injection dynamics, enabling the realization of organic functional integrated circuits with ultrafast nonvolatile memory matrices.