Texturierte Zinkoxidschichten für Silizium-Dünnschichtsolarzellen
Texturierte Zinkoxidschichten für Silizium-Dünnschichtsolarzellen
This thesis addresses the development of surface-textured ZnO:Al films prepared bymagnetron sputtering and post deposition wet chemical etching. Technological goal is thedesign of optimised light trapping schemes for amorphous (a-Si:H) and microcrystalline ($\mu$c-Si:H) silicon based thin film solar...
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Personal Name(s): | Kluth, Oliver (Corresponding author) |
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Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
2001
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Physical Description: |
IX, 150 p. |
Document Type: |
Report Book |
Research Program: |
Addenda |
Series Title: |
Berichte des Forschungszentrums Jülich
3928 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
This thesis addresses the development of surface-textured ZnO:Al films prepared bymagnetron sputtering and post deposition wet chemical etching. Technological goal is thedesign of optimised light trapping schemes for amorphous (a-Si:H) and microcrystalline ($\mu$c-Si:H) silicon based thin film solar cells. A comprehensive material study an sputtered ZnO:Alis presented focusing an the relationship between film growth, structural film properties andthe resulting surface morphology obtained after etching in hydrochloric acid. The ZnO:Alfilms were prepared using rf and dc magnetron sputtering from ceramic and metallic targets,respectively. Deposition pressure and substrate temperature are found to have the majorinfluence an the ZnO:Al material properties. With both deposition techniques highlyconductive (p=2-3*10$^{-4}\Omega$cm) and transparent ZnO:Al films are prepared applying low sputterpressures. The deposition pressure also controls the structural film properties which arereflected by distinctly different surface morphologies after etching as characterised by atomicforce microscopy and Scanning electron microscopy. ZnO:Al films with compact filmstructure develop a crater-like surface morphology with characteristic distribution, lateral sizeand depth of the surface features due to anisotropic etching. Increasing the deposition pressureresults in less dense films leading to reduced opening angles and greater depth of the craters.Exceeding a certain pressure value a transition to a hill-like surface structure is observed,typical for ZnO:Al films with low density. A modified Thornton growth model is proposed toexplain the experimental observations in terms of the structural film properties. The materialresults serve as basis for the development of ZnO/glass substrates and ZnO/Ag back reflectorswith adapted surface texture for superstrate (p-i-n) and substrate (n-i-p) silicon thin film solarcells. Solar cells prepared on these substrates yield initial efficiencies of 8.7% for a $\mu$c-Si nipcell, 10.2% and 11.2 % for a-Si/a-Si and a-Si/$\mu$c-Si pin tandem cells, respectively. |