Study of Cu/In/Se/Se thin films prepared by the Stacked Elemental Layer (SEL) technique

CuInSe2 thin films have been grown on Corning glass and Si (100) substrates using stacked elemental layers (SEL) processing. The influence of substrate’s nature and substrate’s temperature were studied. X-ray diffraction and SEM measurements have shown that the films exhibit an excellent crystallinity and crystallize in a tetragonal structure. Scanning electron microscopy investigations have shown that the films consist in a structure with large grains in the range 80 – 200 nm. Increasing the deposition temperature from room temperature to 300 °C has lead to a change in the composition and morphology of the films. Characteristic peaks of the chalcopyrite structure such as (101), (211) and (311) were clearly observed for both layers upon annealing at 450°C as evidenced by X-ray diffraction study. The determined lattice parameters were a = 0.57725 (6) nm, b = 1.1621 (2) nm for sample prepared at room temperature and a = 0.57770 (4) nm, b = 1.1602 (1) nm for Ts = 300°C. The crystallographic structure of the CuInSe2 sample was analyzed by Rietveld analysis using X-ray powder diffraction data. UV-Vis-NIR Spectrophotometry was used to investigate the optical characteristics of different Cu/In/Se/Se thin layers in the spectral range between 300 – 2000 nm. The optical band-gap of our materials increases from 0.98 to 1.01 eV

Influence de la fréquence et du désordre atomique sur l'effet acousto-électrique

On étudie l'influence de la fréquence et du désordre atomique sur l'effet acousto-électrique dans un système composé de deux plaques : semi-conducteur sur substrat piézo-électrique. Les dislocations d'un semi-conducteur soumis à l'action d'une onde acoustique effectuent des vibrations mécaniques autour de leur position d'équilibre. Il en résulte un désordre atomique et une augmentation dans la concentration des défauts. L'analyse détaillée de la différence de potentiel acousto-électrique permet d'une part d'étudier les propriétés physiques générales de la plaque piézo-électrique et d'autre part de mettre en évidence l'influence du désordre sur la mobilité des porteurs de charge du semi-conducteur

Influence de la fréquence et du désordre atomique sur l'effet acousto-électrique

We study the influence of the frequency and the atomic disorder on the acoustoelectric effect in a system ; semiconductor on a piezoelectric substrat. When a semiconductor is subjected to an acoustic wave, the dislocations perform mechanical vibrations around their equilibrium position. It results an atomic disorder and an increase in the concentration of the defects. The detailled analysis of the acoustoelectric voltage allows to study the general physical properties of the piezoelectric wave guide and the influence of the disorder on the mobility of the semiconductor charge carriers.On étudie l'influence de la fréquence et du désordre atomique sur l'effet acousto-électrique dans un système composé de deux plaques : semi-conducteur sur substrat piézo-électrique. Les dislocations d'un semi-conducteur soumis à l'action d'une onde acoustique effectuent des vibrations mécaniques autour de leur position d'équilibre. Il en résulte un désordre atomique et une augmentation dans la concentration des défauts. L'analyse détaillée de la différence de potentiel acousto-électrique permet d'une part d'étudier les propriétés physiques générales de la plaque piézo-électrique et d'autre part de mettre en évidence l'influence du désordre sur la mobilité des porteurs de charge du semi-conducteur

Photoluminescence of polycrystalline CuIn0.5Ga0.5Te2 thin films grown by flash evaporation

International audienc

Study of microcrystalline silicon Thin Films prepared by PECVD with the characterization of metal-semiconductor contact

National audienc

Study of microcrystalline silicon Thin Films prepared by PECVD with the characterization of metal-semiconductor contact

National audienc

DC and high-frequency conductivity of CuInSe2 bulk crystals

International audienceBulk crystals of CuInSe2 (CIS) were grown by vacuum fusion technique with specific proportions of Cu, In and Se. The studied samples, cut from the central part of the ingots, were first characterised by scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy. The conductivity of the crystals was investigated by using a contactless technique based on hyper-frequency microwave. The method consisted in measurements made in a rectangular resonance cavity at 9192 MHz. Conductivity has been also measured by conventional Van der Paw method and the values obtained, varied in the range [3.10-3-7.10-3]Ω-1cm-1, didn't show significant discrepancies between the two techniques

DC and high-frequency conductivity of CuInSe2 bulk crystals

International audienceBulk crystals of CuInSe2 (CIS) were grown by vacuum fusion technique with specific proportions of Cu, In and Se. The studied samples, cut from the central part of the ingots, were first characterised by scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy. The conductivity of the crystals was investigated by using a contactless technique based on hyper-frequency microwave. The method consisted in measurements made in a rectangular resonance cavity at 9192 MHz. Conductivity has been also measured by conventional Van der Paw method and the values obtained, varied in the range [3.10-3-7.10-3]Ω-1cm-1, didn't show significant discrepancies between the two techniques

Synthesis and characterization of thermally evaporated Cu2SnSe3 ternary semiconductor

International audienceCopper Tin Selenide (CuSnSe) powder was mechanically alloyed by high energy planetary ball milling,starting from elemental powders. Synthesis time and velocity have been optimized to produce Cu2SnSe3materials. Thin films were prepared by thermal evaporation on Corning glass substrate at Ts = 300 C. Thestructural, compositional, morphological and optical properties of the synthesized semiconductor havebeen analyzed by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), scanning electronmicroscopy (SEM) and transmission electron microscopy. The analyzed powder exhibited a cubic crystalstructure, with the presence of Cu2Se as a secondary phase. On the other hand, the deposited filmsshowed a cubic Cu2SnSe3 ternary phase and extra peaks belonging to some binary compounds. Furthermore,optical measurements showed that the deposited layers have a relatively high absorptioncoefficient of 105 cm1 and present a band gap of 0.94 eV