Fabrication and characterization of transparent p-n and p-i-n heterojunctions prepared by spray pyrolysis technique: Effect of post-annealing process and intrinsic middle layer

In this paper, p-n and p-i-n heterojunctions based on transparent semiconducting oxides are fabricated employing the spray pyrolysis technique. The prepared p-NiO:Li/n-SnO2:F (bi-layer) and p-NiO:Li/i-ZnO/n-SnO2:F (tri-layer) junctions are structurally, electrically and optically characterized, and the effect of insertion of the intrinsic buffer layer (i-ZnO) followed by post-annealing is investigated through I-V measurements. The measurement results for the proposed p-NiO:Li/n-SnO2:F device show that the forward threshold and the reverse breakdown voltages are about 0.4 and -2.8 V. respectively. By applying the middle layer, the forward threshold and reverse breakdown voltages reach similar to 1 and -4.2 V; then by post-annealing this element at 700 degrees C for 30 min, the mentioned voltages reach about 1.6 and -3.1 V. respectively. (c) 2010 Elsevier B.V. All rights reserved.