| Autor: |
Barzic, Andreea Irina, Albu, Raluca Marinica, Stoica, Iuliana, Varganici, Cristian Dragos, Hulubei, Camelia |
| Předmět: |
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| Zdroj: |
Polymer Bulletin; Apr2023, Vol. 80 Issue 4, p4503-4522, 20p |
| Abstrakt: |
The current trends in solar energy industry are directed toward lower costs, while driving the performance of the devices to higher efficiency and extended applicability. The rigid cover glass represents a large proportion of the device weight and also requires significant expenses. This work proposes four polyimides (PIs) containing cycloaliphatic units and chalcogen atoms as alternative materials shielding of the solar cells with low weight and better flexibility. The main investigation is focused on the PI solution properties, namely on their rheological involvement in obtaining uniform coatings upon processing via tape casting procedure. The structural peculiarities of each polymer sample are reflected in their response to shear deformation. Depending on the intensity of the imposed shear rate, the PI solution displays Newtonian or pseudoplastic flow. As the chain flexibility is higher, the analyzed liquids exhibit a more pronounced shear rate-dependent viscosity. The shear stress curves are described by Ostwald model, which enable the assessment of the consistency and flow indices of the prepared PI solutions. Velocity and shear rates profiles are evaluated to elucidate the shear intensity beneath the casting blade and transfer these data in the rheological curves. The decrease in the flow index determines higher thickness of the PI coating, while larger uniformity of thickness is attained when the casting speed exceeds 12 mm/s. Wettability of the PI solution on adjacent transparent conductive oxide from the solar cell is also tested. These results are relevant for establishing the adequate conditions for processing polymer solutions for solar cell applications. The thermal, morphological and optical tests are made for additionally proving the suitability of these structures for the pursued goal. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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