Wafer-Scale Carbon Nanotubes Diodes Based on Dielectric-Induced Electrostatic Doping.

Zhang, Xinyue; Sun, Pengkun; Wei, Nan; Si, Jia; Li, Xiaojing; Ba, Jinhan; Wang, Jiawen; Qin, Dongshun et al. · ACS Nano · 2024

basic_science · Level V

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Abstract

Diodes based on p-n junctions are fundamental building blocks for numerous circuits, including rectifiers, photovoltaic cells, light-emitting diodes (LEDs), and photodetectors. However, conventional doping techniques to form p- or n-type semiconductors introduce impurities that lead to Coulomb scattering. When it comes to low-dimensional materials, controllable and stable doping is challenging due to the feature of atomic thickness. Here, by selectively depositing dielectric layers of Y<sub>2</sub>O<sub>3</sub> and AlN, direct formation of wafer-scale carbon-nanotube (CNT) diodes are demonstrated with high yield and spatial controllability. It is found that the oxygen interstitials in Y<sub>2</sub>O<sub>3</sub>, and the oxygen vacancy together with Al-Al bond in AlN/Y<sub>2</sub>O<sub>3</sub> electrostatically modulate the intrinsic CNTs channel, which leads to p- and n-type conductance, respectively. These CNTs diodes exhibit a high rectification ratio (>10<sup>4</sup>) and gate-tunable rectification behavior. Based on these results, we demonstrate the applicability of the diodes in electrostatic discharge (ESD) protection and photodetection.