Title: Optimisation of the physical properties of InAs/InGaAs/GaAs QDs heterostructures embedded p-i-n GaAs solar cell

Authors: Maher Ezzdini; Bilel Azeza; Saoussen Rekaya; Mohamed Helmi Hadj Alouane; Larbi Sfaxi; Ridha M'ghaieth; Nicolas Chauvin; Hassen Maaref; Catherine Bru-Chevallier

Addresses: Laboratoire de Micro-optoélectronique et Nanostructures (LMON), Université de Monastir, Monastir, Tunisia ' Laboratoire de Micro-optoélectronique et Nanostructures (LMON), Université de Monastir, Monastir, Tunisia ' Laboratoire de Micro-optoélectronique et Nanostructures (LMON), Université de Monastir, Monastir, Tunisia ' Laboratoire de Micro-optoélectronique et Nanostructures (LMON), Université de Monastir, Monastir, Tunisia; Institut des Nanotechnologies de Lyon (INL)-UMR5270-CNRS, INSA-Lyon, 7 avenue Jean Capelle, 69621 Villeurbanne, France ' Laboratoire de Micro-optoélectronique et Nanostructures (LMON), Université de Monastir, 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-optoélectronique et Nanostructures (LMON), Université de Monastir, Monastir, Tunisia ' Institut des Nanotechnologies de Lyon (INL)-UMR5270-CNRS, INSA-Lyon, 7 avenue Jean Capelle, 69621 Villeurbanne, France ' Laboratoire de Micro-optoélectronique et Nanostructures (LMON), Université de Monastir, Monastir, Tunisia ' Institut des Nanotechnologies de Lyon (INL)-UMR5270-CNRS, INSA-Lyon, 7 avenue Jean Capelle, 69621 Villeurbanne, France

Abstract: In order to enhance absorption at infrared range for GaAs-based solar cell, we have grown multi-stacked InAs/InGaAs/GaAs quantum dots (QDs) heterostructure in the active region by Solid-Source Molecular Beam Epitaxy (SS-MBE). Two different families of dots were observed in the photoluminescence (PL) spectra. Temperature-dependent study was carried out at 10-240 K temperature range. Distinctive, asymmetric shape located in the high energy for the PL spectra of the QD solar cell sample can be deconvoluted in two sub-bands. From the temperature-dependent PL measurement, the two sub-bands are associated with the ground-state emission from the two families of InAs dots with different size. Besides, the spectral response of multi-stacked InAs/InGaAs QD solar cells extends the photo-absorption spectra towards a wavelength longer than the GaAs bandgap of 1280 nm. However, the QDs solar cell shows an enhanced short-circuits current density of 7.8 mA/cm² compared to the GaAs reference cell. The performance of the QD solar cells indicates that the InAs/InGaAs/GaAs QD heterostructures facilitate the fabrication of highly stacked QD layers that are suitable for solar cells devices requiring thick QD layers for sufficient light absorption.

Keywords: quantum dots; QDs; solar cells; InAs; indium arsenide; GaAs; gallium arsenide; molecular beam epitaxy; light absorption; nanotechnology.

DOI: 10.1504/IJNT.2013.053514

International Journal of Nanotechnology, 2013 Vol.10 No.5/6/7, pp.433 - 444

Published online: 27 Apr 2013 *

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