One-dimensional phosphorus doped ZnO nanowires and nanonails are prepared on Si substrate without employing any metal catalyst by chemical vapor deposition method. Field-emission scanning electron microscopy shows that the samples located downstream 1.5 cm away from the source material are of nanowire structure and located 1 cm above source materials of nanonail structure, and the growth mechanisms of phosphorus doped ZnO nanostructures with different morphologies are discussed. The photoluminescence properties of phosphorus doped ZnO nanowires and nanonails are studied at a temperature of 10 K. The phosphorus related acceptor emissions are observed. Furthermore, the current-voltage (I-V) measurement based on the ZnO nanostructures/Si heterojunctions shows a typical semiconductor rectification characteristic with positive open electric fields being 4.8 and 3.2 V, respectively.