Overcoming the Technological Challenges of Contacting Homogeneous High Sheet Resistance Emitters (HHSE)
| Autor: | Ebong, A., Cooper, I.B., Rounsaville, B., Rohatgi, A., Borland, W., Carroll, A.F., Mikeska, K. |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: | |
| DOI: | 10.4229/26theupvsec2011-2bv.3.52 |
| Popis: | 26th European Photovoltaic Solar Energy Conference and Exhibition; 1747-1749 Contacting homogeneous high sheet resistance emitter (HHSE) with the current screen-printing (SP) technology is challenging to the industry. This is due to inability to make uniform HHSE to circumvent local points of high series resistance, which normally control the series resistance of a solar cell. Because of this, the front Ag paste must be able to contact emitters with a wide range of sheet resistance to accommodate such non-uniformities. In this paper we report on successful contacting of HHSE with emitter sheet resistance variation of ≥40-Ω/ with commercial front Ag paste PV16A from Dupont. We investigated this through the fabrication of cells with emitter sheet resistances of 65, 75, 85, 95 and 105- contacted with the same SP H-pattern having 65 gridlines and 3 bus bars in order to assess accurately, without shading effect, the impact of the sheet resistance on open circuit voltage (VOC) and short circuit current density (JSC). We found that emitter sheet resistance in the range of 65-105-Ω/ low average series resistance (RSERIES) of 0.711-1.05-Ω-cm2 and high fill factor (FF) of 0.768-0.787. The 85 and 95-Ω/ emitter gave the best average efficiency of 18.3%, followed by 18.2% for the 65 and 75 Ω/ 8.1% for the 105-Ω/ is is the first ever screen-printed contact with 18.1% efficiency on 105-Ω/ HHSE. The slightly low FF of 76.8% is due to higher series resistance, which can be attributed to emitter resistance since the gridline spacing used was not optimized for such high sheet resistance. However, the shunt resistance and ideality factor were excellent, which suggests the paste is not encroaching the shallow emitter junction. |
| Databáze: | OpenAIRE |
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