Interface-Engineered Al:IZTO/Tellurium Heterojunction TFTs with Ultra-Thin Al ₂ O ₃ for Tunable Double Turn-On and NDR Characteristics in Logic Applications

We propose an all-oxide p-n heterojunction thin-film transistor (H-TFT) based on Tellurium (Te)/Al-doped In-Zn-Sn-O (Al:IZTO) stack with an ultra-thin (sub-2 nm) Al2O3interlayer. In this architecture, n-type TFTs are demonstrated with Te functioning as an electron-blocking and hole-conducting layer, and Al2O3acting as a tunneling barrier and interface passivation layer, enhancing interfacial control and Te crystallinity. By engineering these layers, we achieve threshold voltage (VTH) shifts of up to +20 V with increasing Te thickness (4–8 nm), second turn-on modulation via Al-doped In–Zn–Sn–O (Al:IZTO) thickness (10–20 nm) with peak-to-valley ratio (PVR) exceeding 100, and distinct negative differential resistance (NDR) in long channel devices. A ternary logic inverter is configured using this structure, exhibiting three distinct output states (Logic 0, 1, 2) based on the device’s dual turn-on behavior, highlighting its potential for MVL applications using fully oxide-based devices.