Evaluation of Series Resistance Losses in Screen-Printed Solar Cells With Local Rear Contacts
Evaluation of Series Resistance Losses in Screen-Printed Solar Cells With Local Rear Contacts
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DOI：
10.1109/jphotov.2011.2163925
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发表时间：
2011-07-01
影响因子：
3
通讯作者：
Brendel, Rolf
中科院分区：
文献类型：
--
作者：
Gatz, Sebastian;Dullweber, Thorsten;Brendel, Rolf
我们展示了工业上可行的大面积太阳能电池与钝化同质发射极和背面实现高达19.4%的能量转换效率的125毫米x 125毫米p型2-3 Omega.cm硼掺杂直拉硅晶片。前、后金属触点通过丝网印刷银和铝浆并在传统带式炉中烧制而制成。然而，由于串联电阻增加，这些单元遭受低于76%的中等填充因子。在本文中，我们分析了这种增长的主要原因。我们在很大范围内改变后接触几何形状。通过从测得的串联电阻中减去基极的相应贡献，我们提取了丝网印刷局部铝后触点的有效比触点电阻率的值（55 +/- 10）Omega.cm（2）。我们通过来自光致发光测量的局部串联电阻映射来验证该值，导致接触电阻率为（40 +/- 10）m Omega.cm（2）。我们的分析表明，进一步提高能量转换效率的最大潜力是降低后接触电阻率。
We demonstrate industrially feasible large-area solar cells with passivated homogenous emitter and rear achieving energy conversion efficiencies of up to 19.4% on 125 mm x 125mm p-type 2-3 Omega.cm boron-doped Czochralski silicon wafers. Front and rear metal contacts are fabricated by screen printing of silver and aluminum paste and firing in a conventional belt furnace. However, these cells suffer from moderate fill factors below 76% due to an increased series resistance. In this paper, we analyze the main cause of this increase. We vary the rear contact geometry over a wide range. By subtracting the respective contribution of the base from the measured series resistance, we extract a value of (55 +/- 10) m Omega.cm(2) for the effective specific contact resistivity of our screen-printed local aluminum rear contacts. We verify this value by local series resistance mappings from photoluminescence measurements resulting in a contact resistivity of (40 +/- 10) m Omega.cm(2). Our analysis reveals that the highest potential for a further energy conversion efficiency improvement is to decrease the rear contact resistivity.