Nanocrystalline thin film silicon solar cells: A deeper look into p/i interface formation
| Autor: | Joaquim P. Leitão, Hugo Águas, Tiago Mateus, António Vicente, Andriy Lyubchyk, Bruno P. Falcão, Rodrigo Martins, Manuel J. Mendes, Sergej Filonovich, Elvira Fortunato |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
Silicon Ion plating Metals and Alloys Analytical chemistry Nanocrystalline silicon chemistry.chemical_element Surfaces and Interfaces Chemical vapor deposition 7. Clean energy Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention chemistry Plasma-enhanced chemical vapor deposition law Solar cell Materials Chemistry Thin film Layer (electronics) |
| Zdroj: | Thin Solid Films |
| ISSN: | 0040-6090 |
| Popis: | The p/i interface plays a major role in the conversion efficiency of nanocrystalline silicon (nc-Si:H) solar cells. Under plasma-enhanced chemical vapor deposition (PECVD) of the intrinsic (i) nc-Si:H layer, ion bombardment can severely affect the underlying p-doped layer and degrade the solar cell performance. The core of the present work is to investigate the effect of light and heavy ion bombardment on the structural modifications of the p-layer during the p/i interface formation. The properties of the nc-Si:H materials deposited under distinct conditions are analyzed and correlated to the deposition rate and the resulting cell efficiency. To recreate the ion bombardment during the initial stages of the i-layer deposition on the p-layer, hydrogen plasma treatment was performed for 30 s (light ion bombardment), after which a flux of silane was introduced into the deposition chamber in order to initiate the heavy ion bombardment and growth of an ultra-thin (5 nm) i-layer. The structural changes of the p-type nc-Si:H layers were observed by spectroscopic ellipsometry. The obtained results confirm that detrimental structural modifications (e.g. partial amorphization of the sub-surface region and bulk) occur in the p-layer, caused by the ion bombardment. To minimize this effect, a protective buffer layer is investigated able to improve the performance of the solar cells fabricated under increased growth rate conditions. |
| Databáze: | OpenAIRE |
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