Investigation on the Ag-Al Metal Spiking into Boron-Diffused p+ Layer of Industrial Bifacial n-Type Silicon Wafer Solar Cells by Numerical Simulation
| Autor: | Li, M., Ma, F.-J., Stangl, R., Aberle, A.G., Samudra, G.S., Hoex, B. |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: | |
| DOI: | 10.4229/eupvsec20172017-2ao.4.5 |
| Popis: | 33rd European Photovoltaic Solar Energy Conference and Exhibition; 251-255 A small amount of Al is usually added to the Ag paste to facilitate a sufficiently low specific contact resistance to contact boron diffused p+ silicon layers. However, Al can result in spiking from the metal contacts into the diffused layer leading to a pronounced recombination at the metal-silicon interface. This significantly limits the open-circuit voltages of screen printed n-type silicon solar cells. The aim of this work is to investigate the sensitivity of industrially feasible boron diffusion doping profiles to various spike densities/shapes using Sentaurus TCAD device simulation. Four different experimental BBr3 diffused doping profiles were analyzed. Bifacial n-type front and back contacted (nFAB) silicon solar cells were simulated. It was found that the cell efficiency was only significantly affected when the localized spikes penetrate as deep as that they contact to a doping density below ~ 1×10^18 cm-3. Beyond that point, the defect-related recombination at the metal-Si interface starts to increase by orders of magnitude. The cell efficiency could degrade by relatively ~ 2 - 3 % to up to ~ 10 % when the spike fraction increases from 5 - 10 % to 100 %. |
| Databáze: | OpenAIRE |
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