Electrical, Photoelectrical and Morphological Properties of ZnO Nanofiber Networks Grown on SiO2 and on Si Nanowires

Journal article

ZnO nanofibre networks (NFNs) were grown by vapour transport method on Si-based substrates. One type of substrate was SiO2 thermally grown on Si and another consisted of a Si wafer onto which Si nanowires (NWs) had been grown having Au nanoparticles catalysts. The ZnO-NFN morphology was observed by scanning electron microscopy on samples grown at 600 °C and 720 °C substrate temperature, while an focused ion beam was used to study the ZnO NFN/Si NWs/Si and ZnO NFN/SiO2 interfaces. Photoluminescence, electrical conductance and photoconductance of ZnO-NFN was studied for the sample grown on SiO2. The photoluminescence spectra show strong peaks due to exciton recombination and lattice defects. The ZnO-NFN presents quasi-persistent photoconductivity effects and ohmic I-V characteristics which become nonlinear and hysteretic as the applied voltage is increased. The electrical conductance as a function of temperature can be described by a modified three dimensional variable hopping model with nanometer-ranged typical hopping distances. © 2013.

Authors: Celeste Vega, N; Tirado, M; Comedi, D; Rodriguez, A; Rodriguez, T

• Publication status: Published
• Journal: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS
• Volume: 16
• Issue: 3
• Pages: 597-602
• Publication date: 2013-01-01
• DOI: 10.1590/S1516-14392013005000030
• ISSN: 1516-1439
• Language: English
• Keywords: nanostructures; photoconductivity; photoluminescence; semiconductors; ZnO