Exploring the practical efficiency limit of silicon solar cells using thin solar-grade substrates
Exploring the practical efficiency limit of silicon solar cells using thin solar-grade substrates
复制标题
探索使用薄太阳能级基板的硅太阳能电池的实际效率极限
DOI：
10.1039/d0ta04575f
复制
发表时间：
2020
影响因子：
11.9
通讯作者：
King, R. R.
中科院分区：
文献类型：
--
作者：
Augusto, A.;Karas, J.;Balaji, P.;Bowden, S. G.;King, R. R.
多种硅太阳能电池技术的效率已经超过或接近超过26%。电介质和非晶硅基钝化层与最小的金属/硅接触面积相结合，可将表面饱和电流密度降低到 3 fA cm−2 以下。在开路时，在钝化接触太阳能电池中，复合主要来自基本机制（俄歇和辐射），占总复合的 3/4 以上。在最大功率点，随着表面和体肖克利-雷德-霍尔介入，基本复合分数可降至一半。因此，为了进一步提高工作点的性能，减少体依赖性并确保适当的表面钝化至关重要。可以通过降低体缺陷密度或减小晶圆厚度来减轻体复合。我们证明，对于商业上可行的太阳能级硅，需要更薄的晶圆和低于 1 fA cm−2 的表面饱和电流密度，才能将太阳能电池的实际效率极限显着提高至 0.6% 绝对值。对于 10 ms 的高质量 n 型体硅少数载流子寿命，最佳晶圆厚度范围为 40–60 μm，这与之前假设未掺杂衬底和仅俄歇复合和辐射复合计算的 110 μm 的值有很大不同。在此厚度范围内，需要接近 0.1 fA cm−2 的表面饱和电流密度才能缩小与基本效率极限的差距。我们通过实验证明，不同晶圆厚度（35-170 μm）的 pi/CZ/in 结构上的表面饱和电流低于 0.5 fA cm−2，有可能达到接近 770 mV 的开路电压和接近 350 mV 的带隙电压偏移。最后，我们使用带隙电压偏移作为指标来比较文献中冠军实验太阳能电池的质量，以及最具商业相关性的光伏电池吸收器和架构。
Multiple silicon solar cell technologies have surpassed or are close to surpassing 26% efficiency. Dielectric and amorphous silicon-based passivation layers combined with minimal metal/silicon contact areas were responsible for reducing the surface saturation current density below 3 fA cm−2. At open-circuit, in passivated contact solar cells, the recombination is mainly from fundamental mechanisms (Auger and radiative) representing over 3/4 of the total recombination. At the maximum power point, the fundamental recombination fraction can drop to half, as surface and bulk Shockley–Read–Hall step in. As a result, to further increase the performance at the operating point, it is paramount to reduce the bulk dependence and secure proper surface passivation. Bulk recombination can be mitigated either by reducing bulk defect density or by reducing the wafer thickness. We demonstrate that for commercially-viable solar-grade silicon, thinner wafers and surface saturation current densities below 1 fA cm−2, are required to significantly increase the practical efficiency limit of solar cells up to 0.6% absolute. For a high-quality n-type bulk silicon minority-carrier lifetime of 10 ms, the optimum wafer thickness range is 40–60 μm, a very different value from 110 μm previously calculated assuming undoped substrates and solely Auger and radiative recombination. In this thickness range surface saturation current densities near 0.1 fA cm−2 are required to narrow the gap towards the fundamental efficiency limit. We experimentally demonstrate surface saturation currents below 0.5 fA cm−2 on pi/CZ/in structures across different wafer thicknesses (35–170 μm), with potential to reach open-circuit voltages close to 770 mV and bandgap-voltage offsets near 350 mV. Finally, we use the bandgap-voltage offset as a metric to compare the quality of champion experimental solar cells in the literature, for the most commercially-relevant photovoltaic cell absorbers and architectures.
登录
查看更多内容
硅片厚度对晶硅异质结太阳能电池光伏性能的影响
影响因子：
1.5
作者：
H. Sai;Hiroshi Umishio;T. Matsui;S. Nunomura;T. Kawatsu;H. Takato;K. Matsubara
通讯作者：
K. Matsubara
一个太阳中的掺杂表面，点接触太阳能电池
DOI：
--
发表时间：
1989
期刊：
影响因子：
--
作者：
R. King;R. Sinton;R. M. Swanson
通讯作者：
R. M. Swanson
影响因子：
3
作者：
Schaefer, Soeren;Brendel, Rolf
通讯作者：
Brendel, Rolf
影响因子：
6.7
作者：
B. Stegemann;K. M. Gad;P. Balamou;Daniel Sixtensson;D. Vossing;M. Kasemann;H. Angermann
通讯作者：
B. Stegemann;K. M. Gad;P. Balamou;Daniel Sixtensson;D. Vossing;M. Kasemann;H. Angermann
影响因子：
56.7
作者：
Yoshikawa, Kunta;Kawasaki, Hayato;Yamamoto, Kenji
通讯作者：
Yamamoto, Kenji