Memristive InAs-Based Semiconductors with Anisotropic Ion Transport

The use of the van der Waals (vdW) gap as an ion migration path, similar to cathode materials in lithium-ion batteries, enables improved ion migration. If these materials also possess semiconductor properties, they can simultaneously control electron or hole transport. Such materials can be used in memtransistors, which combine memory and semiconductor characteristics. However, the existing materials rely on defects such as grain boundaries as migration paths, resulting in high ion migration energy barriers and switching voltages. Herein, memtransistors are demonstrated using H_xNa_2-xIn₂As₃, which utilizes the vdW gap for ion migration, resulting in lower ion migration energy barriers. It is confirmed that ion migration occurs more readily in the [010] direction in a low-symmetry crystal structure owing to a lower migration energy barrier, whereas migration does not occur in the [100] direction, demonstrating directional dependence. This finding provides crucial guidelines for identifying ion migration in semiconductor materials, which can otherwise be overlooked. The use of the vdW gap as the migration path, variation in migration energy barriers with the ion movement direction, and their impact on low power consumption are critical factors that will guide the future development of memtransistor materials.