Study of boron diffusion for p plus emitter of large area N-type TOPCon silicon solar cells
Study of boron diffusion for p plus emitter of large area N-type TOPCon silicon solar cells
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大面积N型TOPCon硅太阳能电池p+发射极硼扩散研究
DOI：
10.1007/s00339-020-03851-5
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发表时间：
2020
影响因子：
2.7
通讯作者：
Qu Hui
中科院分区：
文献类型：
--
作者：
Zhou Ying;Tao Ke;Liu Aimin;Jia Rui;Jiang Shuai;Bao Jianhui;Yang Sanchuan;Cao Yujia;Qu Hui
采用硼掺杂（BCl 3）热扩散制备的硼掺杂发射极已被用于N型隧道氧化物钝化接触（TOPCon）硅太阳能电池中。为了建立一种适合于TOPC太阳电池制备的p +发射极扩散工艺，研究了扩散压力、预沉积O2流量和驱入O2流量对薄膜的掺杂分布、薄层电阻、BSG厚度以及薄层电阻均匀性的影响。此外，研究了BSG厚度对TOPCon电池的表面形貌和光学特性的影响。实验结果表明，在低压（300 mbar）下，p +发射极的均匀性较好，方块电阻可接受。此外，在p +发射极上设置一层厚的BSG（> 50 nm）是非常必要的，它可以在去除环绕多晶硅的过程中有效地保护下面的发射极。最后，基于硼扩散发射极的244.32cm ~ 2 n型TOPCon太阳能电池获得了22%以上的高效率，薄层电阻为70-90欧姆/平方，BSG厚度约100 nm。
Boron doped emitters prepared by thermal diffusion using boron trichloride (BCl3) have been adopted in N-type Tunnel Oxide Passivated Contact (TOPCon) silicon solar cells. In order to establish a proper diffusion process of p + emitter that matches to TOPCon solar cells fabrication, the influence of diffusion pressure, pre-deposition O2flow rate and drive-in O2flow rate on the doping profiles, sheet resistance, BSG thickness as well as the sheet resistance uniformity are carefully investigated. In addition, the impact of BSG thickness on the surface morphology and optical properties of the TOPCon cells are studied. The experimental results indicate that good uniformity of p + emitter can be obtained at low pressure (300 mbar) with acceptable sheet resistance. In addition, a p + emitter with thick BSG (> 50 nm) layer is very necessary, which can effectively protect the underneath emitter during the removal process of the wrap-around poly-Si. Finally, high efficiency over 22% is obtained for 244.32 cm2n-type TOPCon solar cells based on the boron diffused emitter with the sheet resistance 70–90 ohm/sq., BSG thickness ~ 100 nm.