Open Access Nano Express

Current-voltage characteristics in macroporous silicon/SiOx/SnO2:F heterojunctions

Felipe A Garcés1*, Raul Urteaga12, Leandro N Acquaroli1, Roberto R Koropecki12 and Roberto D Arce12

Author Affiliations

1 , Instituto de Desarrollo Tecnológico para la Industria Química, UNL/CONICET, Güemes 3450, Santa Fe, S3000GLN, Argentina

2 , Facultad de Ingeniería Química,UNL, Santiago del Estero 2829, Santa Fe, S3000AOM, Argentina

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Nanoscale Research Letters 2012, 7:419  doi:10.1186/1556-276X-7-419

Published: 25 July 2012

Abstract

We study the electrical characteristics of macroporous silicon/transparent conductor oxide junctions obtained by the deposition of fluorine doped-SnO2 onto macroporous silicon thin films using the spray pyrolysis technique. Macroporous silicon was prepared by the electrochemical anodization of a silicon wafer to produce pore sizes ranging between 0.9 to 1.2 μm in diameter. Scanning electronic microscopy was performed to confirm the pore filling and surface coverage. The transport of charge carriers through the interface was studied by measuring the current-voltage curves in the dark and under illumination. In the best configuration, we obtain a modest open-circuit voltage of about 70 mV and a short-circuit current of 3.5 mA/cm2 at an illumination of 110 mW/cm2. In order to analyze the effects of the illumination on the electrical properties of the junction, we proposed a model of two opposing diodes, each one associated with an independent current source. We obtain a good accordance between the experimental data and the model. The current-voltage curves in illuminated conditions are well fitted with the same parameters obtained in the dark where only the photocurrent intensities in the diodes are free parameters.

Keywords:
Macroporous silicon; Transparent conductor oxide; Spray pyrolysis; Electrical anodization