Emitter Degradation Induced by a Rear Laser-Firing Process in Silicon Heterojunction Solar Cells
| Autor: | Morales-Vilches, A.B., Voz Sánchez, C., Colina Brito, M., Martín, I., Ortega, P., Orpella, A., López, G., Alcubilla González, R. |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: | |
| DOI: | 10.4229/eupvsec20142014-2av.2.36 |
| Popis: | 29th European Photovoltaic Solar Energy Conference and Exhibition; 893-896 The optimization of the emitter in silicon heterojunction (SHJ) solar cells is of key importance to obtain high-efficiency devices. In our case, the emitter consists of a very thin stack (~15 nm) of hydrogenated amorphous silicon (a-Si:H) layers coated by a 80 nm thick indium-tin-oxide antireflection electrode. A novel laserfiring process has been applied on the rear side to contact our complete devices based on p-type wafers. Particularly, a pulsed Nd-YAG infrared laser (1064 nm) was used to locally diffuse aluminium contacts through an alumina/a- SiCx:H passivating stack. In this work we investigate the damage that this laser-firing process could induce in the emitter because of an overheating of the sample at this step. Two parallel fabrication processes of SHJ solar cells have been implemented varying only the order of the laser treatment to investigate its influence on the emitter surface. An effective lifetime about a 30% higher was measured in device precursors for which the emitter was deposited after the laser-firing step. Also for this fabrication sequence the open-circuit voltage of complete devices was more than 25 mV higher. These results suggest that a degradation of the heterojunction emitter could be taking place during the laser-firing process. |
| Databáze: | OpenAIRE |
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