Vertically aligned p-type ZnO (Li-N co-doped) nanowires have been synthesized by hydrothermal method on n-type Si substrate. X-ray diffraction pattern indicated a strong peak from (0 0 0 2) planes of ZnO. The appearance of a strong peak at 437 cm(-1) in Raman spectra was attributed to E-2 mode of ZnO. Fourier transformed infrared studies indicated the presence of a distinct characteristic absorption peaks at 490 cm(-1) for ZnO stretching mode. Compositional studies revealed the formation of Li-N co-doped ZnO, where Li was bonded with both O and N. The junction properties of p-type ZnO nanowires/n-Si heterojunction diodes were evaluated by measuring I-V and C-V characteristics. I-V characteristics exhibited the rectifying behavior of a typical p-n junction diode. (C) 2010 Elsevier B.V. All rights reserved.