21.0%-efficient co-diffused screen printed n-type silicon solar cell with rear-side boron emitter
| Autor: | Jan Schmidt, Nadine Wehmeier, Bianca Lim, Thorsten Dullweber, Anja Nowack, Rolf Brendel |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
Silicon chemistry.chemical_element Nanotechnology 02 engineering and technology 01 natural sciences law.invention chemistry.chemical_compound law Saturation current Plasma-enhanced chemical vapor deposition 0103 physical sciences Solar cell General Materials Science Boron Common emitter 010302 applied physics business.industry Energy conversion efficiency 021001 nanoscience & nanotechnology Condensed Matter Physics chemistry Optoelectronics 0210 nano-technology business Diborane |
| Zdroj: | physica status solidi (RRL) - Rapid Research Letters. 10:148-152 |
| ISSN: | 1862-6254 |
| DOI: | 10.1002/pssr.201510393 |
| Popis: | Plasma enhanced chemical vapor deposition (PECVD) is applied to deposit boron silicate glasses (BSG) acting as boron diffusion source during the fabrication of n-type silicon solar cells. We characterize the resulting boron-diffused emitter after boron drive-in from PECVD BSG by measuring the sheet resistances Rsheet,B and saturation current densities J0,B. For process optimization, we vary the PECVD deposition parameters such as the gas flows of the precursor gases silane and diborane and the PECVD BSG layer thickness. We find an optimum gas flow ratio of SiH4/B2H6= 8% and layer thickness of 40 nm. After boron drive in from these PECVD BSG diffusion sources, a low J0,B values of 21 fA/cm2 is reached for Rsheet,B = 70 Ω/□. The optimized PECVD BSG layers together with a co-diffusion process are implemented into the fabrication process of passivated emitter and rear totally diffused (PERT) back junction (BJ) cells on n-type silicon. An independently confirmed energy conversion efficiency of 21.0% is achieved on 15.6 × 15.6 cm2 cell area with a simplified process flow. This is the highest efficiency reported for a co-diffused n-type PERT BJ cell using PECVD BSG as diffusion source. A loss analysis shows a small contribution of 0.13 mW/cm2 of the boron diffusion to the recombination loss proving the high quality of this diffusion source. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) |
| Databáze: | OpenAIRE |
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