- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
The impact of interstitial Fe contamination on n-type Cz-Silicon for high efficiency solar cells
摘要： In this work, we have investigated the impact of interstitial Fe contamination on the effective minority carrier lifetime of n-type Cz silicon bulk material for high efficiency solar cells. The study covers a Fe concentration in the silicon bulk from 3.5 ? 1012 cm-3 to 2.7 ? 1014cm-3. We have added 5 different concentrations (30, 100, 300, 1000 and 3000 ppb) of Fe intentionally to a wet chemical process tank and measured the transfer to the silicon wafer surface mimicking a possible contamination during wet chemical processing. In order to fabricate carrier lifetime test vehicles, the silicon wafer is then passivated with thermal silicon oxide from both sides. The surface contamination is driven into the bulk by mimicking a high temperature process during solar cell manufacturing. Effective minority carrier lifetime is measured at injection levels from 1 ? 1013 cm-3 to 3 ? 1015cm-3. We have fitted the theoretical curve for interstitial Fe derived from the SRH theory to the measured values and extracted the Fe contamination concentration. This value is comparable to the calculated value extracted from the surface contamination measurement. For low level injection (LLI), we extracted the capture cross section for interstitial Fe to be 6.45 ? 10-17 cm/s ? 2.23 ? 10-17 cm/s. The measured Fe contamination levels are used for the conversion efficiency fitting of a n-type bifacial silicon solar cell using QUOKKA simulations. The simulations show that very low Fe contamination concentrations of [Fe]bulk ? 3.5 ? 1012 cm-3 ([Fe]surf ? 6 ? 1010cm-2) already degrade the solar cell efficiency by 10% relative.
关键词： Effective minority carrier lifetime,Interstitial Fe Contamination,QUOKKA simulations,n-type Si Solar cell,High efficiency
更新于2025-09-23 15:19:57
-
Effective minority carrier lifetime as an indicator for potential-induced degradation in p-type single-crystalline silicon photovoltaic modules
摘要： In this paper, we report the effective minority carrier lifetime (τeff) in fresh and potential-induced degradation (PID) acceleration tested p-type single-crystalline Si modules. τeff in different regions of solar cells was measured using the microwave photoconductance decay (μPCD) method. Electroluminescence (EL), lock-in-thermography, and dark and light current–voltage (I–V ) measurements were carried out as a complementary analysis of μPCD. In addition, τeff in every stage of Si solar cell fabrication (wafer to solar cell) was measured to investigate the change of carrier dynamics. From the obtained results, a great decrease in τeff was observed in the PID-affected regions, confirming the excess non-radiative recombination centers in that region, suggesting that τeff from the μ-PCD method can be an effective indicator to judge whether PID phenomenon has occurred.
关键词： microwave photoconductance decay,p-type single-crystalline silicon,potential-induced degradation,effective minority carrier lifetime,photovoltaic modules
更新于2025-09-11 14:15:04