Carrier transport mechanism on ZnO nanorods/p-Si heterojunction diodes with various atmospheres annealing hydrothermal seed-layer

► Annealing in various atmospheres (vacuum, N2, and O2) for hydrothermal seed-layers. ► Carrier transport in ZnO nanorods (NRs)/p-Si heterojunction diodes (HJDs). ► Vacuum-annealed ZnO NRs/p-Si HJDs demonstrate recombination-tunnelling transport. ► N2- and O2-annealed ZnO NRs/p-Si HJDs reveal diffusion-recombination transport. ► Large rectification ratio of 1.9 × 105 in the O2-annealed ZnO NRs/p-Si HJDs.