Improvement of sol‐gel ZnO heterojunctions by hydrogen annealing

E-ISSN： 1610-1642|7|2|288-291

ISSN： 1862-6351

Source： PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Vol.7, Iss.2, 2010-02, pp. : 288-291

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Abstract

AbstractZnO films were formed quartz substrates and silicon (100) wafers by a sol‐gel technique, and they were crystallized (in air at 800 °C) and annealed in hydrogen (at 220 to 420 °C, for 10 to 120 min). Photoluminescence (PL) measurements of ZnO films on quartz substrates indicated that hydrogen annealing increased the near band edge (NBE) emission ten‐fold, but it only slightly decreased the deep level emission (DLE). Hall effect measurements showed an n‐type conduction of the films, with an electron concentration of about 10¹⁶ cm^–3, Hall mobility of about 14 cm²/Vs, and resistivity of about 2 Ωcm. Before hydrogen annealing, n‐ZnO/p‐Si heterojunctions showed only ohmic behavio. After hydrogen annealing, however, the forward current was increased and the reverse current was decreased, and the final I‐V curve showed a typical rectifying characteristicc. These results can be explained by a conventional polycrystalline and grain boundary (GB) model with a potential barrier height near the GBs and defects in the grains. (© 2010 WILEY‐VCH Verlag GmbH Co. KGaA, Weinheim)