posted on 2024-03-05, 14:35authored byXinyue Zhang, Pengkun Sun, Nan Wei, Jia Si, Xiaojing Li, Jinhan Ba, Jiawen Wang, Dongshun Qin, Ningfei Gao, Lei Gao, Haitao Xu, Lian-Mao Peng, Ying Wang
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 Y2O3 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 Y2O3, and the oxygen vacancy together with
Al–Al bond in AlN/Y2O3 electrostatically
modulate the intrinsic CNTs channel, which leads to p- and n-type
conductance, respectively. These CNTs diodes exhibit a high rectification
ratio (>104) and gate-tunable rectification behavior.
Based
on these results, we demonstrate the applicability of the diodes in
electrostatic discharge (ESD) protection and photodetection.