Growth and Characterization of Urea Doped p-Type ZnO Thin Film Grown by Pulsed Laser Deposition
In the present study we have used urea as the source for doping nitrogen in ZnO since the most successful acceptor type dopant is the group V element like nitrogen. The nitrogen doped ZnO films have been deposited on glass substrates using Pulsed Laser Deposition technique using 248 nm KrF laser at energy 300 mJ by varying the number of laser pulses with a repetition rate of 10 pulse/sec in vacuum (10-6 mbar) at a constant temperature of 300 °C. The XRD pattern confirms the formation of wurtzite structure of ZnO, which is polycrystalline in nature. We have also performed UV absorption spectroscopy and the band gap is found to be 3.4 eV. Resistivity of the film increases with the increase of thickness for the undoped ZnO samples where the carrier concentrations are found to be of the order of 1017 cm-3. The mobility of the as-grown film is found to be 24.9 cm2/V-s. After doping with nitrogen the carrier concentration drops to the order of 1015 cm-3 and the mobility becomes 1.5 cm2/V-s. The mobility slightly varies with thickness. The resistivity increases to 1.3 KΩ-cm and the film shows p-type behavior. The results are explained on the basis of the available theory.
S. Ray, S.K. Nath, A. Kumar, R.C. Agarwala, V. Agarwala, G.P. Chaudhari, B.S.S. Daniel
M. Sayanee and B. Pallab, "Growth and Characterization of Urea Doped p-Type ZnO Thin Film Grown by Pulsed Laser Deposition", Advanced Materials Research, Vol. 67, pp. 127-130, 2009