https://doi.org/10.1051/epjap/2010143
Synthesis and characterization of GaAs thin films grown on ITO substrates
1
Centre de Recherches et des Technologies de l'Énergie, Laboratoire de
Photovoltaïque, BP 95, Hammam-Lif, 2050, Tunisia
2
Faculté des Sciences de Gabès, Cité Riadh, Zirig, 6072 Gabès, Tunisia
3
Laboratoire d'Énergétique et Électrochimie des Solides,
Université de Sétif, Sétif, 19000, Algeria
Corresponding author: m.chamekh@yahoo.fr
Received:
17
September
2009
Revised:
25
June
2010
Accepted:
9
August
2010
Published online:
8
October
2010
Gallium arsenide (GaAs) thin films have been deposited on ITO-coated glass substrates from acid aqueous solution by electrodeposition technique. The structure and the morphology of the samples were analyzed by X-ray diffraction (XRD) and atomic force microscope (AFM). The optical characteristics were investigated at room temperature using a UV-Vis spectrometer. At lower deposition time, the XRD patterns exhibit a mixture of both cubic and orthorhombic GaAs phases. With further increase of the film thickness, only orthorhombic structure was observed with a preferred (100) orientation. By applying the Debye-Scherrer method, the estimated crystallite size for the (200) orientation ranged from 30 to 50 nm, whereas for the (022) orientation was found to be 13–22 nm. From the AFM measurements, the rms surface roughness ranged between 11.4 and 18.4 nm. The analysis of the optical absorption data of the annealed GaAs film deposited at different times revealed direct band gap energy in the range of 1.60–1.85 eV. The large blueshifts observed in this study can be fully explained by the Burstein-Moss effect.
© EDP Sciences, 2010
