We demonstrate the fabrication of a fully screen‐printed p‐type silicon solar cell with local hole‐collecting Al‐alloyed (Al‐p⁺) contacts with a record open circuit voltage of 716 mV. The solar cell is fabricated by using almost the same process equipment as PERC cells. One of the dominant recombination losses in PERC cells is the recombination in the passivated and in the contacted emitter regions that so far limit the open circuit voltage to values below 700 mV. We eliminate these loss channels by substituting the P‐diffused emitter by a passivating n‐type poly‐Silicon on Oxide (nPOLO) contact. We place this contact on the rear side because of its otherwise strong parasitic absorption. The Al‐p⁺ contacts are also located at the rear side to avoid front‐side shading. This results in a POLO‐IBC cell structure. The efficiency of the best cell so far is 23.0% with a designated area of 4 cm² fabricated on a M2‐sized wafer. Scanning electron microscopy reveals an Al‐p⁺ thickness of less than 3.3 μm and only a few 100 nm at the contact ends, which is less than the 5 μm typically for optimized Al‐p⁺ contacts. A comparison of measured and simulated current‐voltage curves over a variation of the contact fraction extracts a high saturation current density of the Al‐p⁺ contact of J_{0‐Al ‐p+} = 2,250 fA cm⁻² for the current screen‐print conditions and Al‐paste causing an absolute efficiency loss of 0.5%_abs. The recombination at the AlO_x/SiN_y surface and the shunt resistance limits the cell by 0.6%_abs each.

中文翻译：

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具有本地Alp +和n型POLO叉指背触点的全丝网印刷硅太阳能电池，VOC为716 mV，效率为23％

我们演示了完全丝网印刷的p型硅太阳能电池的制造，该电池具有局部空穴收集的铝合金（Alp ⁺）触点，其开路电压为716 mV，创下了记录。通过使用与PERC电池几乎相同的处理设备来制造太阳能电池。PERC电池中的主要重组损失之一是钝化区和接触发射极区中的重组，到目前为止，这种重组将开路电压限制在700 mV以下。通过用钝化的n型氧化硅（nPOLO）触点代替P扩散的发射极，我们消除了这些损耗通道。我们将这种触点放置在背面，因为它否则会有很强的寄生吸收能力。铝⁺触点也位于背面，以避免正面阴影。这将产生POLO-IBC单元结构。到目前为止，在M2尺寸的晶圆上制造的指定面积为4 cm ²的最佳电池效率为23.0％。扫描电子显微镜显示Al-p ^+的厚度小于3.3μm，并且在接触端只有几百nm，比优化的Al-p ⁺接触通常小于5μm 。比较接触分数变化的实测和模拟电流-电压曲线可得出J _{0-Al-p +} = 2,250 fA cm ^-2的Al-p ⁺触点的高饱和电流密度对于当前的丝网印刷条件和Al-paste，绝对效率损失为0.5％_abs。AlO _x / SiN _y表面的重组和分流电阻分别将电池限制为0.6％_abs。