ACTA

Crystal Growth of CuGaSe₂ Compound for Tandem Photovoltaic Devices

H. Felfli^a, B. Hadjoudja^a, A. Khadraoui^a, S. Gagui^a, B. Zaidi^b, B. Chouial^a, A. Chibani^a
^aLaboratory of Semiconductors, Department of Physics, University Badji Mokhtar, Annaba, Algeria
^bDepartment of Physics, Faculty of Material Sciences, University of Batna 1, Algeria

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In this work, we have investigated the crystal growth of the CuGaSe₂ chalcopyrite structure compound which is intended for tandem photovoltaic devices. Analyses by X-ray diffraction have shown that the obtained ingots are polycrystalline and have a chalcopyrite structure. The preferential orientation along the plane (112) - very suitable for photovoltaic conversion - was obtained. The lattice parameters a and c were calculated from the X-ray spectra, the ratio c/a was found to be near to 2. The use of an energy dispersive spectrometer (EDS) for the analysis of the chemical composition of the constituents showed that the investigated sample had a stoichiometric ratio Cu/In =0.99. The morphological analysis performed using a scanning electron microscope (SEM) has shown that the CuGaSe₂ compound has a well-crystallized appearance with an average grain size of about 3 μm. Characterizations by Hall effect measurements and resistivity have shown that the prepared ingot exhibits a p-type conductivity and low resistivity, of the order of 12.73 Ω cm. The measurement of the photoconductivity of the prepared compound has allowed us to determine the value of the gap at room temperature. The gap was found to be near 1.68 eV. The results obtained within the framework of this study have shown that the prepared CuGaSe₂ compound has good crystalline and optoelectronic properties, which makes it one of the ideal compounds to be used as the top cell for a tandem photovoltaic device.

DOI:10.12693/APhysPolA.139.655
topics: CuGaSe₂, crystal growth, synthesis, tandem photovoltaic device