Channel-Type Engineering in an InSe-Based Transistor: Paving a Way for Next-Generation Reconfigurable Electronics

Achieving reversible n/p-type switching in two-dimensional semiconductors is crucial for reconfigurable nanoelectronic devices. Here, we demonstrate a fully reversible channel-type conversion in InSe-based transistors via ultraviolet-ozone oxidation and thermal annealing, enabling stable bidirectional polarity switching. Electrical, spectroscopic, and microscopic analyses reveal that the reversible-type conversion originates from the intercalation and elimination of oxygen in layered InSe. Density functional theory confirms that oxygen intercalation introduces electron states above the valence band maximum, leading to p-type conduction. Furthermore, an InSe-based inverter and complementary logic gates ("NAND" and "NOR") were fabricated. Finally, an InSe-based p-n homojunction exhibits a high forward-to-reverse current ratio (I_F/I_R > 10⁶) and self-powered photodetection with specific detectivity above 10¹² Jones. This work provides a fundamental demonstration of reversible channel-type engineering in layered semiconductors, offering potential pathways for future developments in reconfigurable electronics.