Improving the performance of GaInP solar cells through rapid thermal annealing and delta doping
Improving the performance of GaInP solar cells through rapid thermal annealing and delta doping
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DOI：
10.1016/j.solmat.2022.111725
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发表时间：
2022-07
影响因子：
6.9
通讯作者：
Yukun Sun;Brian D. Li;R. Hool;S. Fan;Mijung Kim;M. Lee
中科院分区：
文献类型：
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作者：
Yukun Sun;Brian D. Li;R. Hool;S. Fan;Mijung Kim;M. Lee
我们表明，快速热退火（RTA）对分子束外延生长的 GaInP 载流子寿命的影响很大程度上取决于掺杂类型和密度，并且必须考虑这些差异以实现高性能 GaInP 太阳能电池。虽然轻掺杂的p-和n-GaInP的光致发光强度和寿命在RTA后得到了很大的改善，但重掺杂的n+-GaInP在RTA后表现出急剧的退化，阻碍了低发射极薄层电阻的GaInP前结太阳能电池的实现。由于低串联电阻对于实现高填充因子 (FF) 非常重要，因此我们设计了一种前结电池，采用薄型轻掺杂 n 型发射极和 delta 掺杂来增强电导率，从而实现 1.40 V 的开路电压 (VOC) 和 86% 的 FF。然后，我们设计了后异质结太阳能电池，以进一步利用轻 n 掺杂 GaInP (∼19 ns) 相对较长的寿命。借助 n-AlInP 窗口中的 δ 掺杂来改善表面钝化，我们获得了 1.42 V 的 VOC，类似于金属有机气相外延生长的电池。
We show that the effect of rapid thermal annealing (RTA) on carrier lifetime in GaInP grown by molecular beam epitaxy depends strongly on both doping type and density, and that these disparities must be accounted for to realize high-performance GaInP solar cells. Although the photoluminescence intensity and lifetime of lightly doped p- and n-GaInP improved greatly with RTA, heavily doped n+-GaInP showed sharp degradation upon RTA, preventing the realization of GaInP front-junction solar cells with low emitter sheet resistance. Since a low series resistance is important to achieve high fill factor (FF), we designed a front-junction cell utilizing a thin, lightly doped n-type emitter with delta doping to enhance conductivity, attaining an open-circuit voltage (VOC) of 1.40 V and FF of 86%. We then designed rear-heterojunction solar cells to further leverage the relatively long lifetime of lightly n-doped GaInP (∼19 ns). With the help of delta doping in the n-AlInP window to improve surface passivation, we attained a VOCof 1.42 V, similar to cells grown by metal-organic vapor phase epitaxy.