Porous silicon as an internal reflector in thin epitaxial solar cells
| Autor: | J. Poortmans, Filip Duerinckx, K. Van Nieuwenhuysen, I. Kuzma-Filipek, Robert Mertens, Guy Beaucarne |
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| Rok vydání: | 2007 |
| Předmět: |
Materials science
Silicon Spreading resistance profiling business.industry Doping chemistry.chemical_element Surfaces and Interfaces Condensed Matter Physics Porous silicon Epitaxy Surfaces Coatings and Films Electronic Optical and Magnetic Materials Active layer law.invention Optics chemistry law Solar cell Materials Chemistry Optoelectronics Electrical and Electronic Engineering Thin film business |
| Zdroj: | physica status solidi (a). 204:1340-1345 |
| ISSN: | 1862-6319 1862-6300 |
| DOI: | 10.1002/pssa.200674332 |
| Popis: | Thin film epitaxial silicon solar cells are considered a near future alternative to bulk silicon solar cells. However due to the limited thickness of the active layer they require efficient light trapping. Therefore we propose the development and implementation of such light confinement by means of a porous silicon (PS) intermediate reflector at the epi/substrate interface. The formation of the reflector is done by electrochemical etching of a highly doped Si substrate into a multilayer stack (Bragg-optical reflector), and is followed by epitaxial deposition of the active layer. The implementation of the PS reflector however requires detailed analysis of many problematic issues, foremost the optical optimisation of the stack for internal reflection at the Si/PS/Si interface. Other topics include the pore rearrangement during high-temperature CVD as well as the quality of the epitaxial layer grown on porous silicon. Another challenge is the resistance within the PS layers. For that purpose, SRP (Spreading Resistance Probe) and resistance measurements were performed to determine the conductive properties of rearranged PS. First cells with a 9-layer porous silicon reflector gave a very promising efficiency of 13.5% which is 1.5% higher compared to cells without internal reflector. |
| Databáze: | OpenAIRE |
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