Growth of Na-doped ZnO thin films by low-pressure metal organic chemical vapor deposition method was realized using cyclopentadienylsodium as the sodium source. Secondary ion mass spectrometry measurements revealed the existence of Na in the ZnO thin films. Low-temperature scanning tunneling microscopy and scanning tunneling spectroscopy were used for obtaining local density of states (LDOS) of the Na-doped ZnO thin films at nanometer scale. The local measurements indicated a spatial distribution of the LDOS as well as the conductivity type that could be linked to spatial variations of Na doping level. (C) 2013 Elsevier B.V. All rights reserved.