SiNx and AlOx nanolayers in hole selective passivating contacts for high efficiency silicon solar cells
The recombination of photogenerated charge carriers at metal-semiconductor interfaces remains a major source of efficiency loss in photovoltaic cells. Here, we present SiN x and AlO x nanolayers as promising interface dielectrics to enable high efficiency hole selective passivating contacts. It is d...
| Principais autores: | , , , , , , , , , , |
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| Formato: | Journal article |
| Idioma: | English |
| Publicado em: |
IEEE
2022
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| _version_ | 1826309221484855296 |
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| author | McNab, S Niu, X Khorani, E Wratten, A Morisset, A Grant, NE Murphy, JD Altermatt, PP Wright, M Wilshaw, PR Bonilla, RS |
| author_facet | McNab, S Niu, X Khorani, E Wratten, A Morisset, A Grant, NE Murphy, JD Altermatt, PP Wright, M Wilshaw, PR Bonilla, RS |
| author_sort | McNab, S |
| collection | OXFORD |
| description | The recombination of photogenerated charge carriers at metal-semiconductor interfaces remains a major source of efficiency loss in photovoltaic cells. Here, we present SiN x and AlO x nanolayers as promising interface dielectrics to enable high efficiency hole selective passivating contacts. It is demonstrated that SiN x deposited via direct plasma enhanced chemical vapour deposition can be grown controllably at thicknesses of 2 nm. The valence band offsets between crystalline silicon and ultrathin AlO x and SiN x nanolayers are measured as 3.5 and 1.4 eV, respectively. This predicts a larger tunnelling current for holes, compared to SiO x used typically. Resistivity measurements show that SiN x and AlO x nanolayers have lower contact resistivities compared to SiO x , with values as low as 100 mΩ·cm 2 . Analysis of the current transport mechanisms confirmed that tunnelling dominates the conduction through SiN x , while a mixture of tunnelling and pinholes are present in the AlO x structure. Lifetime measurements gave initial indications of the passivation quality of the films, with just 10 cycles of AlO x achieving 260 μ s after annealing and 1.9 ms with extrinsic field effect passivation added. Finally, the intrinsic built-in charge in the dielectrics was determined using surface photovoltage measurements and simulations are used to estimate the influence of nanolayer built-in charge in both poly-Si and dopant-free passivating contacts to enable future high efficiency solar cells. |
| first_indexed | 2024-03-07T07:30:54Z |
| format | Journal article |
| id | oxford-uuid:be849e6c-9ccc-4de2-83d3-5ef4b99b0ea0 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:30:54Z |
| publishDate | 2022 |
| publisher | IEEE |
| record_format | dspace |
| spelling | oxford-uuid:be849e6c-9ccc-4de2-83d3-5ef4b99b0ea02023-01-16T14:23:51ZSiNx and AlOx nanolayers in hole selective passivating contacts for high efficiency silicon solar cellsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:be849e6c-9ccc-4de2-83d3-5ef4b99b0ea0EnglishSymplectic ElementsIEEE2022McNab, SNiu, XKhorani, EWratten, AMorisset, AGrant, NEMurphy, JDAltermatt, PPWright, MWilshaw, PRBonilla, RSThe recombination of photogenerated charge carriers at metal-semiconductor interfaces remains a major source of efficiency loss in photovoltaic cells. Here, we present SiN x and AlO x nanolayers as promising interface dielectrics to enable high efficiency hole selective passivating contacts. It is demonstrated that SiN x deposited via direct plasma enhanced chemical vapour deposition can be grown controllably at thicknesses of 2 nm. The valence band offsets between crystalline silicon and ultrathin AlO x and SiN x nanolayers are measured as 3.5 and 1.4 eV, respectively. This predicts a larger tunnelling current for holes, compared to SiO x used typically. Resistivity measurements show that SiN x and AlO x nanolayers have lower contact resistivities compared to SiO x , with values as low as 100 mΩ·cm 2 . Analysis of the current transport mechanisms confirmed that tunnelling dominates the conduction through SiN x , while a mixture of tunnelling and pinholes are present in the AlO x structure. Lifetime measurements gave initial indications of the passivation quality of the films, with just 10 cycles of AlO x achieving 260 μ s after annealing and 1.9 ms with extrinsic field effect passivation added. Finally, the intrinsic built-in charge in the dielectrics was determined using surface photovoltage measurements and simulations are used to estimate the influence of nanolayer built-in charge in both poly-Si and dopant-free passivating contacts to enable future high efficiency solar cells. |
| spellingShingle | McNab, S Niu, X Khorani, E Wratten, A Morisset, A Grant, NE Murphy, JD Altermatt, PP Wright, M Wilshaw, PR Bonilla, RS SiNx and AlOx nanolayers in hole selective passivating contacts for high efficiency silicon solar cells |
| title | SiNx and AlOx nanolayers in hole selective passivating contacts for high efficiency silicon solar cells |
| title_full | SiNx and AlOx nanolayers in hole selective passivating contacts for high efficiency silicon solar cells |
| title_fullStr | SiNx and AlOx nanolayers in hole selective passivating contacts for high efficiency silicon solar cells |
| title_full_unstemmed | SiNx and AlOx nanolayers in hole selective passivating contacts for high efficiency silicon solar cells |
| title_short | SiNx and AlOx nanolayers in hole selective passivating contacts for high efficiency silicon solar cells |
| title_sort | sinx and alox nanolayers in hole selective passivating contacts for high efficiency silicon solar cells |
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