Fabrication of Cu(In,Ga)Se2 solar cells with a single graded band profile
Fabrication of Cu(In,Ga)Se2 solar cells with a single graded band profile
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具有单梯度能带分布的 Cu(In,Ga)Se2 太阳能电池的制造
DOI：
10.1002/pssb.201400305
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
A. Yamada
中科院分区：
文献类型：
--
作者：
Takahito Nishimura;S. Kasashima;Y. Hirai;Y. Kurokawa;A. Yamada
研究发现，具有单梯度(SG)带隙和平均带隙Eg(Avg)为1.15 eV的CuIn，Ga)Se_2(CIGS)太阳电池的效率高于相同Eg(Avg)的双梯度(DG)带隙，尽管在SG-CIGS/CIGS界面没有刻意加宽带隙。为了解释这一矛盾，我们重点研究了CDS/CIGS界面的能带结构，并提出这种矛盾可以通过在CIGS表面形成有序空位的黄铜矿化合物(OVC)层来解释。利用wxAMPS进行的器件模拟表明，如果界面处存在OVC层，由于界面处表面复合的抑制，SG-CIGS太阳电池的转换效率优于DG-CIGS太阳电池，从而导致开路电压(VOC)的改善。我们将这种结构应用于高Ga含量的CIGS太阳电池。结果表明，Eg(Avg)为1.4 eV的SG-CIGS太阳电池的转换效率为15.1%，而DG-CIGS太阳电池的转换效率为12.9%。这一效率可与高Ga含量CIGS太阳电池的最高效率相媲美。因此，SG能带分布是一种很有前途的结构，有望在高Ga含量的CIGS太阳电池中实现本质上预测的高效率。
It was found that Cu(In,Ga)Se2 (CIGS) solar cells with single graded (SG) band profile and average bandgap Eg(avg) of 1.15 eV has higher efficiency than double graded (DG) band profile with the same Eg(avg), despite no intentional bandgap‐widening at a CdS/CIGS interface in SG‐CIGS. To explain this contradiction, we focused on the band structure at the CdS/CIGS interface and proposed that the contradiction can be explained by the formation of an ordered vacancy chalcopyrite compound (OVC) layer on the surface of CIGS. Device simulation using wxAMPS revealed that if an OVC layer exists at the interface, conversion efficiency of SG‐CIGS solar cells overcomes that of DG‐CIGS solar cells due to suppression of surface recombination at the interface, leading to open‐circuit voltage (VOC) improvement. We applied the SG structure to CIGS solar cells with high Ga contents. As a result, the conversion efficiency of 15.1% for the SG‐CIGS solar cell with Eg(avg) of 1.4 eV was achieved, although in contrast, that of the DG‐CIGS solar cells was 12.9%. This efficiency is comparable to the highest efficiency in CIGS solar cells with high Ga contents. Therefore, SG band profile is promising structure and it is expected to achieve high efficiency predicted essentially in CIGS solar cells with high Ga contents.
影响因子：
6.7
作者：
Jackson, Philip;Hariskos, Dimitrios;Powalla, Michael
通讯作者：
Powalla, Michael