Laser-fired contacts for p-type c-Ge TPV devices
Thermophotovoltaic (TPV) systems, which convert radiant heat into electricity, have become the most efficient heat-to-electricity technology. However, efforts to reduce its cost must still be prioritized to make it commercially competitive. Our research group focuses on epitaxial-free TPV devices us...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/442340 |
| Acceso en línea: | https://hdl.handle.net/2117/442340 https://dx.doi.org/10.1016/j.solmat.2025.113837 |
| Access Level: | acceso abierto |
| Palabra clave: | Germanium TPV Laser-fired contacts Àrees temàtiques de la UPC::Energies Àrees temàtiques de la UPC::Energies::Energia solar tèrmica |
| Sumario: | Thermophotovoltaic (TPV) systems, which convert radiant heat into electricity, have become the most efficient heat-to-electricity technology. However, efforts to reduce its cost must still be prioritized to make it commercially competitive. Our research group focuses on epitaxial-free TPV devices using crystalline germanium (c-Ge) as an absorber. Following this cost-effective approach, in this work we specifically report on partially contacted rear surfaces on p-type c-Ge devices defined by laser-firing aluminium films through a dielectric passivating layer, leading to the so-called laser-fired contacts. This approach has been successfully adopted in silicon solar cells and was explored in early c-Ge TPV devices, but posed many technological challenges. In this work, we use an infrared (¿ = 1064 nm) laser and commercial p-type c-Ge wafers (1.2 O cm) passivated with a Al2O3/a-SiC film stack. By ToF-SIMS measurements, we confirm that part of the aluminium is diffused inside the c-Ge substrate creating p+ regions. Additionally, by adjusting the aluminium thickness and the laser parameters, we are able to control the size of the spot while minimizing substrate damage. Optimized contacts lead to contact resistivity of 7.2·10-5 O cm2 and a surface recombination velocity at the contact of 1075 cm/s. As a proof of concept, this rear surface is introduced into c-Ge photovoltaic devices measured under 1 sun illumination, with a remarkable efficiency of 6.29 %. The obtained results suggest the potential of the contacts to be integrated in c-Ge devices optimized for TPV conditions. |
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