Cu In,Ga Se2 surface treatment with Na and NaF A combined photoelectron spectroscopy and surface photovoltage study in ultra high vacuum
| Autor: | Wolfram Calvet, V. Parvan, Bünyamin Ümsür, E. Avancini, A. Mizrak, Iver Lauermann, Thomas Dittrich, Christian A. Kaufmann, I. Majumdar, Dieter Greiner |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Solar cells of the next generation Materials science Surface photovoltage Ultra-high vacuum Analytical chemistry General Physics and Astronomy 02 engineering and technology Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Surfaces Coatings and Films Metal Band bending X-ray photoelectron spectroscopy visual_art 0103 physical sciences visual_art.visual_art_medium Surface layer Thin film 0210 nano-technology Spectroscopy |
| Popis: | Either metallic Na or NaF were deposited onto Cu(In,Ga)Se2 surfaces and studied by photoelectron spectroscopy and surface photovoltage spectroscopy without breaking the ultra-high vacuum. The deposition of elemental Na at room temperature led to the formation of an intermediate Cu and Ga rich layer at the CIGSe surface, whereas for NaF the composition of the CIGSe surface remained unchanged. A metal like surface induced by an inverted near surface region with a reduced number of defect states was formed after the deposition of Na. Under the chosen experimental conditions, the near surface layer was independent on the amount of Na and stable in time. In contrast, the usage of NaF weakened the inversion and led to an increased band bending compared to the untreated CIGSe sample. The SPV signals decreased with proceeding time after the deposition of NaF. |
| Databáze: | OpenAIRE |
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