Quantification of pn-junction recombination in interdigitated back-contact crystalline silicon solar cells
| Autor: | Bas W. H. van de Loo, Ilkay Cesar, Pierpaolo Spinelli, Wilhelmus M. M. Kessels, Ard H. G. Vlooswijk |
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| Přispěvatelé: | Plasma & Materials Processing, Atomic scale processing, Processing of low-dimensional nanomaterials |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Passivation Silicon 020209 energy chemistry.chemical_element 02 engineering and technology law.invention Depletion region recombination law Solar cell 0202 electrical engineering electronic engineering information engineering Wafer Crystalline silicon Electrical and Electronic Engineering surface passivation business.industry Energy conversion efficiency Doping 021001 nanoscience & nanotechnology Condensed Matter Physics Electronic Optical and Magnetic Materials chemistry pn-junction solar cells Optoelectronics 0210 nano-technology business p–n junction interdigitated back contact (IBC) |
| Zdroj: | IEEE Journal of Photovoltaics, 7(5):7962148, 1176-1183. IEEE Electron Devices Society |
| ISSN: | 2156-3381 |
| Popis: | Interdigitated back-contact (IBC) solar cells based on diffused crystalline silicon comprise a series of pn -junctions which border at the rear surface of the wafer. In this work, it is established that the presence of these pn -junctions can induce significant additional charge-carrier recombination, which affect the conversion efficiency of IBC cells through a reduction in fill factor and open-circuit voltage. Using specialized test structures with varying length of pn -junctions per area of solar cell (i.e., with varying junction density), the magnitude of the recombination at the pn -junction was determined. For nonpassivated rear surfaces, a second-diode recombination current density per unit of junction density J 02 of ∼61 nA·junction–1·cm–1 was measured, whereas for surfaces which were passivated by either SiN $_{x}$ or Al 2O3/SiN $_{x}$ , J 02 was reduced to ∼0.4 nA·junction–1·cm–1. Therefore, passivation of defects at the rear surface was proven to be vital in reducing this characteristic recombination current. Finally, by optimizing the p - and n -type dopant diffusion process recipes, J 02 recombination could be suppressed. The improved doping recipes led to an increase in conversion efficiency of industrial “mercury” IBC solar cells by ∼1% absolute. |
| Databáze: | OpenAIRE |
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