RESUMO
In a recent publication by Abou-Ras et al., various techniques for the analysis of elemental distribution in thin films were compared, using the example of a 2-µm thick Cu(In,Ga)Se2 thin film applied as an absorber material in a solar cell. The authors of this work found that similar relative Ga distributions perpendicular to the substrate across the Cu(In,Ga)Se2 thin film were determined by 18 different techniques, applied on samples from the same identical deposition run. Their spatial and depth resolutions, their measuring speeds, their availabilities, as well as their detection limits were discussed. The present work adds two further techniques to this comparison: laser-induced breakdown spectroscopy and grazing-incidence X-ray fluorescence analysis.
RESUMO
Quantitative prediction of elemental concentration or concentration ratio of solid samples can be achieved by laser induced breakdown spectroscopy if a calibration curve that is little influenced by plasma conditions could be obtained. This work demonstrates that such a calibration curve is available for copper indium gallium diselenide (CuIn(1-x)Ga(x)Se2) thin film solar cells for properly selected spectral lines. The possible changes of calibration curves based on the selected spectral lines are discussed in consideration of self-absorption in optically thick plasma and the dependency of spectral line properties on plasma temperature.
RESUMO
This work reports the capability of depth profile analysis of thin CuIn1-xGa(x)Se2 (CIGS) absorber layer (1.89 µm) with a sub-hundred nanometer resolution by laser induced breakdown spectroscopy (LIBS). The LIBS analysis was carried out with a commercial CIGS solar cell on flexible substrate by using a pulsed Nd:YAG laser (λ = 532 nm, τ = 5 ns, top-hat profile) and an intensified charge-coupled device spectrometer in atmospheric conditions. The measured LIBS elemental profiles across the CIGS layer agreed closely to those measured by secondary ion mass spectrometry. The resolution of depth profile analysis was about 88 nm. Owing to the short measurement time of LIBS and the capability of in-air measurement, it is expected that LIBS can be applied for in situ analysis of elemental composition and their distribution across the film thickness during development and manufacturing of CIGS solar cells.
RESUMO
The authors report that the elemental composition ratio of Ga to In in a CuIn(1-x)Ga(x)Se(2) compound semiconductor, a thin-film solar cell material, can be measured with little influence of plasma property changes by laser-induced breakdown spectroscopy (λ = 1064 nm, τ = 5 ns). It is shown that the similarity in excitation energy levels of the selected Ga and In emission lines and the fact that these elements belong to the same group of the periodic table are the critical factors ensuring the independence of intensity ratio on plasma conditions.
RESUMO
In this paper, the glass systems, TeO2-ZnO-BaO (TZB), TeO2-ZnO-BaO-Nb2O5 (TZB-Nb) and TeO2-ZnO-BaO-MoO3 (TZB-Mo), were fabricated by the traditional melt-quench protocol for use as mid-infrared (mid-IR) transmitting optical material. The effect of Nb2O5 and MoO3 on the key glass material properties was studied through various techniques. From the Raman analysis, it was found that the structural modification was clear with the addition of both Nb2O5 and MoO3 in the TZB system. The transmittance of studied glasses was measured and found that the optical window covered a region from 0.4 to 6 µm. The larger linear refractive index was obtained for the Nb2O5-doped TZB glass system than that of other studied systems. High glass transition temperature, low thermo-mechanical coefficient and high Knoop hardness were noticed in the Nb2O5-doped TZB glass system due to the increase in cross-linking density and rigidity in the tellurite network. The results suggest that the Nb2O5-doped TZB optical glasses could be a promising material for mid-infrared transmitting optics.