Applied Surface Science, Vol.255, No.12, 6141-6144, 2009
Electrical characterization of p-ZnO/p-Si heterojunction
Nitrogen doped p-ZnO film, with urea as nitrogen source, is fabricated by pulsed laser deposition on well-cleaned p-type (1 0 0) Si substrates. The structural and electrical properties of the p-p heterojunction are investigated by current-voltage (I-V) and capacitance-voltage (C-V) measurements. It shows a diode-like behavior with turn-on voltage of 0.5 V. The ideality factor eta determined by applying positive potential in p-ZnO and negative potential along p-Si is found to be 6. Such a high value of h is attributed to lattice mismatch between ZnO and Si. and other factors responsible are thermoionic emission, minority carrier injection and recombination. C-V results indicate an abrupt interface and a band bending of 0.9 V in the silicon. Heterojunction band diagram for p-ZnO/p-Si is proposed. (C) 2009 Elsevier B.V. All rights reserved.