Nitrogen-doped ZnO thin films grown on glass substrates by atomic layer deposition using NH3 as a doping source

Nitrogen-doped ZnO (ZnO:N) films were successfully grown on glass substrates by atomic layer deposition (ALD). NH3 was used as a doping source, and the substrate temperature was relatively low (90 approximately 210 degrees C). The main focus of the study was to report on the effect of the temperature on the electrical properties (e.g., carrier concentration, mobility, etc.) of the grown ZnO:N films. At all temperatures, the carrier was found to be n-type, and its electron concentration did not show much variation within the values between 3 x 10(16) and 6 x 10(16) cm-3; the mobility increased with the temperature (1 cm2/Vs at 110 degrees C, 5 cm2/Vs at 190 degrees C); and the resistivity decreased with the temperature (203 omegacm at 110 degrees C, 21 omegacm at 190 degrees C). The electrical properties are discussed in relation with the nitrogen concentration, crystallinity, crystal orientation, grain size, and surface morphology. The nitrogen concentration in the ZnO:N films was constant at all temperatures (approximately 2.5 atomic percent); the crystallinity and crystal orientation improved with the temperature; and the mean grain size increased with the temperature (13.2 nm at 110 degrees C, 35.3 nm at 190 degrees C). The results for the ZnO:N films were also compared with the results for the undoped ZnO films.