This title appears in the Scientific Report :
2018
Please use the identifier:
http://hdl.handle.net/2128/18058 in citations.
Nanocrystalline Silicon Oxide in Silicon Heterojunction Solar Cells
Nanocrystalline Silicon Oxide in Silicon Heterojunction Solar Cells
To advance the contribution of photovoltaic (PV) systems in a transition towards fully sustainable energy generation, the costs of the associated systems need to decrease. In particular, a constant evolution of their solar energy conversion efficiency ($\eta$) is an effective way to reduce the overa...
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Personal Name(s): | Richter, Alexei (Corresponding author) |
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Contributing Institute: |
Photovoltaik; IEK-5 |
Imprint: |
Jülich
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
2018
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Physical Description: |
166 S. |
Dissertation Note: |
RWTH Aachen, Diss., 2018 |
ISBN: |
978-3-95806-310-5 |
Document Type: |
Book Dissertation / PhD Thesis |
Research Program: |
Solar cells of the next generation |
Series Title: |
Schriften des Forschungszentrums Jülich Reihe Energie & Umwelt / Energy & Environment
416 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
To advance the contribution of photovoltaic (PV) systems in a transition towards fully sustainable energy generation, the costs of the associated systems need to decrease. In particular, a constant evolution of their solar energy conversion efficiency ($\eta$) is an effective way to reduce the overall costs of the energy production of a solar cell. In the recent decade high $\eta$ have been achieved by the silicon heterojunction (SHJ) solar cell technology, which allows for a very high open circuit voltage (Voc). However, the parasitic absorptance (A$_{paras}$) within the doped hydrogenated amorphous silicon (a-Si:H) layers still causes a significant reduction in the short circuit current density (J$_{sc}$) of a SHJ solar cell. In contrast, thin films of hydrogenated nanocrystalline silicon oxide (nc-SiO$_{x}$:H) are significantly more transparent. This is related to their advantageous microstructure, in which a conductive network of crystalline silicon (c-Si) is combined with a silicon dioxide (SiO$_{2}$)-like matrix at the nanoscale. Nevertheless, a trade-off between a high conductivity and a high transparency has to be considered due to the conflicting properties of the two phases. Accordingly, the aim of this thesis was to develop doped nc-SiO$_{x}$:H films at an increased deposition frequency (very high frequency (VHF)) to improve the optoelectronic trade-off of the films. Furthermore, these layers were applied in SHJ solar cells to achieve a low Aparas and, thereby, an enhanced J$_{sc}$. Additionally, a continuous enhancement of $\eta$ was accomplished by changes in the design of the solar cells. In detail, films of nc-SiO$_{x}$:H were optimized at VHF using plasma enhanced chemical vapor deposition (PECVD). By exploiting the increased atomic H density at VHF, an improved phase separation was achieved in comparison to films deposited at radio frequency (RF) within the same deposition system and the [...] |