Due to the advent of nanotechnology, materials can be readily fabricated into nanoscale configurations with different dimensionalities and widely tunable properties for technological applications. In this presentation, we will summarize and discuss the recent progress in our research group, emphasizing the development of various mixed-dimensional hetero-nanostructures, such as (1) 1D GaAsSb nanowire/2D MoS₂ nanoflake heterojunctions for the gate-tunable and anti-ambipolar phototransistor and (2) full-van der Waals (vdWs) 1D p-Te/2D n-Bi₂O₂Se photodiodes with rationally designed nanoscale ultra-photosensitive channels.