Investigations on the passivation mechanism of AlN:H and AlN:H-SiN:H stacks
| Autor: | Georg Krugel, Anamaria Moldovan, Winfried Wolke, Ralf Preu, Franziska Jenkner, Jochen Rentsch |
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| Přispěvatelé: | Publica |
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Materials science
Silicon Passivation chemistry.chemical_element Nitride Lichteinfang Energy(all) Saturation current Plasma-enhanced chemical vapor deposition Electronic engineering Passivierung passivation Oberflächen - Konditionierung Silicon oxide AlN Sputter business.industry Open-circuit voltage Doping nitride Silicium-Photovoltaik chemistry hydrogen Optoelectronics PV Produktionstechnologie und Qualitätssicherung aluminum nitride business |
| Popis: | In this paper, the properties of hydrogenated aluminum nitride layers (AlN:H) as an excellent passivation layer of silicon surfaces are examined. The structural and chemical properties of the AlN:H bulk are analyzed using a great variety of measurements techniques such as GI-XRD, FTIR, SEM, HR-TEM, corona charging and a thickness dependent measurements of the surface passivation. A model for the formation of negative fixed charges at the interface to silicon is presented based on the charge state of ionized point defects in AlN. Additionally, stacks of AlN:H and SiNx:H are introduced into silicon photovoltaics and their combination with two different types of thin low temperature silicon oxide layers is studied. Excellent passivation results are presented for highly doped p-type silicon and highly doped n-type silicon using the previous described stacks. Emitter saturation current densities of textured samples show, that 75 Ω/sq. phosphorous emitter can be passivated as efficient as with the typically used SiNx:H allowing maximum open circuit voltages of 657 mV. This is supported by measurement of cell parameters of p-type solar cells using these stacks as a combined anti-reflective coating and passivation layer. Furthermore, the passivation level reached for high efficiency 70 Ω/sq. boron emitters is nearly as high as with excellent passivating PECVD Al2O3/SiNx stacks. Emitter saturation current densities down to 61 fA/cm2 are presented corresponding to a maximum open circuit voltage of 696 mV. This indicates that the invented stacks containing AlN:H can also be applied as combined anti-reflective coating and passivation layers in n-type cells. |
| Databáze: | OpenAIRE |
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