Highly Efficient Full van der Waals 1D p-Te/2D n-Bi₂O₂Se Heterodiodes with Nanoscale Ultra-Photosensitive Channels

Continuous miniaturization of semiconductor devices is the key to boosting modern electronics development. However, this downscaling strategy has been rarely utilized in photoelectronics and photovoltaics. Here, in this work, a full-van der Waals (vdWs) 1D p-Te/2D n-Bi₂O₂Se heterodiode with a rationally designed nanoscale ultra-photosensitive channel is reported. Enabled by the dangling bond-free mixed-dimensional vdWs integration, the Te/Bi₂O₂Se type-II diodes show a high rectification ratio of 3.6 × 10⁴. Operating with 100 mV reverse bias or in a self-power mode, the photodiodes demonstrate excellent photodetection performances, including high responsivities of 130 A W⁻¹ (100 mV bias) and 768.8 mA W⁻¹ (self-power mode), surpassing most of the reports of other heterostructures. More importantly, a superlinear photoelectric conversion phenomenon is uncovered in these nanoscale full-vdWs photodiodes, in which a model based on the in-gap trap-assisted recombination is proposed for this superlinearity. All these results provide valuable insights in light–matter interactions for further performance enhancement of photoelectronic devices.