Characterization of n-ZnO/p-Si films grown by magnetron sputtering

ZnO films were deposited by RF magnetron Sputtering on single p-Si substrates to form n-ZnO/ p-Si heterojunctions. Various Substrate temperatures of 25. 100, 200, 300 and 400 degrees C were used. The electrical junction properties were characterized by current-voltage (I-V) and capacitance-voltage (C-V) methods. Calculations of the barrier height from classical 1/C-2-V characterizations and from the I-V in dark conditions indicate merely the same values of 0.7 eV. Moreover, the optical spectra showed that the reflectance of the ZnO films grown with different substrate temperatures is inferior to that of bare silicon substrate in the UV and visible region. The smallest reflectance in the visible region was found for films grown at higher Substrate temperature, indicating a possible application of these films as anti-reflection coatings for Si-based optoelectronic devices allowing the minimization of reflection losses. (C) 2005 Elsevier Ltd. All rights reserved.