Title: Characterisation of the GaAs-based intermediate band solar cell with multi-stacked InAs/InGaAs quantum dots

Authors: W. Rouis; A. Sayari; M. Nouiri; M. Ezzdini; S. Rekaya; L. El Mir; L. Sfaxi; H. Maaref

Addresses: Laboratoire de Micro-optoélectroniques et Nanostructures (LMON), Université de Monastir, Tunisia ' Faculty of Science, Department of Physics, King Abdulaziz University, North Jeddah Branch, P.O. Box 80203, Jeddah, Kingdom of Saudi Arabia; Equipe de Spectroscopie Raman, Faculté des Sciences de Tunis, Département de Physique, Campus Universitaire, El-Manar, 2092 Tunis, Tunisia ' Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPHyMNE), Faculty of Sciences in Gabes, Gabes University, Gabes, Tunisia ' Laboratoire de Micro-optoélectroniques et Nanostructures (LMON), Université de Monastir, Tunisia ' Laboratoire de Micro-optoélectroniques et Nanostructures (LMON), Université de Monastir, Tunisia ' Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPHyMNE), Faculty of Sciences in Gabes, Gabes University, Gabes, Tunisia; Al Imam Mohammad Ibn Saud Islamic University (IMSIU), College of Sciences, Department of Physics, Riyadh 11623, Saudi Arabia ' Laboratoire de Micro-optoélectroniques et Nanostructures (LMON), Université de Monastir, Tunisia; Université de Sousse, Ecole Supérieure des Sciences et de Technologie de Hammam Sousse, Rue Lamine Abassi 4011 H. Sousse, Tunisia ' Laboratoire de Micro-optoélectroniques et Nanostructures (LMON), Université de Monastir, Tunisia

Abstract: We report on both the photovoltaic and the optical properties of GaAs p-i-n solar cell (SC) and GaAs p-i-n SC with multiple InAs quantum dot (QD) layers in the i-region. Current-voltage and impedance spectroscopy measurements have been used to characterise the two SC devices. Refractive index, extinction and absorption coefficients were deduced from spectroscopic ellipsometry. I-V measurements in dark and illumination conditions have been carried out to investigate the photovoltaic effect in these devices. Our results suggested that the presence of trap states could cause the degraded photovoltaic performance of the QD SC device. The C-V characteristics of the QD SC device show forward bias region with negative values of capacitance, which is caused by the filling process of the dots near the junction. The equivalent circuit model consisting of two-series connected RC networks with a series resistance R_s was found to give a good fit to the experimental data.

Keywords: quantum dots; solar cells; InAs; InGaAs; indium arsenide; indium gallium arsenide; multi-stacking; GaAs; gallium arsenide; nanotechnology; photovoltaic performance; optical properties; solar energy; solar power.

DOI: 10.1504/IJNT.2015.068880

International Journal of Nanotechnology, 2015 Vol.12 No.8/9, pp.584 - 596

Published online: 17 Apr 2015 *

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