Rotational design of charge carrier transport layers for optimal antimony trisulfide solar cells and its integration in tandem devices
Rotational design of charge carrier transport layers for optimal antimony trisulfide solar cells and its integration in tandem devices
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最佳三硫化锑太阳能电池载流子传输层的旋转设计及其在串联器件中的集成
DOI：
10.1016/j.solmat.2019.110279
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发表时间：
2020-03-01
影响因子：
6.9
通讯作者：
Pang, Jinbo
中科院分区：
文献类型：
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作者：
Cao, Yu;Zhu, Xinyun;Pang, Jinbo
Sb 2S 3薄膜太阳能电池由于其低成本、低毒性和简单的制造而近来受到关注。然而，他们的表现仍有很大的改进空间。众所周知，有效的载流子传输对于高性能Sb 2S 3太阳能电池是必不可少的，不幸的是，这很难通过常规测试方法来表征。因此，本文采用理论模拟的方法研究了Sb_2S_3太阳电池中的载流子输运过程。结果表明，高的太阳能性能可以通过用于选择电子传输层以及空穴传输层的宽的参数窗口来实现，即，具有电子传输层的导带最小值（-4.4eV < CBM <-3.2eV）和空穴传输层的价带最大值（-5.2eV> VBM >-6.4eV）。此时界面势垒可以忽略不计，电子和空穴可以很容易地交叉，保证了器件的良好性能。实际上，通过确保器件中的载流子传输和收集不受阻碍，即，基于Sb 2S 3的单结太阳能电池显示出19.53%的高效率。此外，我们发现优化的Sb 2S 3太阳能电池特别适合用作叠层结构太阳能电池的顶电池。因此，提出了Sb 2S 3/Sb 2Se 3双结太阳能电池结构。当吸收层厚度为0.5 μ m时，双结太阳电池的理论转换效率可达26.64%.我们的研究结果的基础上的旋转设计的带隙排列提供了一个一般的指导原则，选择最佳的电子传输层以及空穴传输层，以提高功率转换效率的Sb 2S 3太阳能电池的理论极限。
Sb2S3 thin-film solar cells have recently gained attention due to their low cost, low toxicity, and simple fabrication. However, there is still plenty of room to improve their performance. It is known that efficient carrier transport is essential for high performance Sb2S3 solar cells, which, unfortunately, is difficult to characterize by conventional testing methods. Therefore, the carrier transport process in Sb2S3 solar cells was studied here using a theoretical simulation. The results show that high solar performances can be achieved with a wide parameter window for selecting the electron transport layer as well as the hole transport layer, viz., with a conduction band minimum of the electron transport layer (-4.4 eV < CBM < -3.2 eV), and a valence band maximum of the hole transport layer (-5.2 eV > VBM > -6.4 eV). Here the interfacial potential barrier become negligible and as a consequence electrons and holes cross at ease, which guarantee the good device performance. Indeed, a Sb2S3 solar cell with a high power conversion efficiency (PCE) can be obtained by ensuring that the carrier transport and collection are unimpeded in the device, i.e., the Sb2S3-based single junction solar cells shows high efficiency of 19.53%. Furthermore, we found that optimized Sb2S3 solar cells are particularly suitable for use as the top cell of tandem structure solar cells. Thus, a Sb2S3/Sb2Se3 double junction solar cell structure was proposed. With a 0.5 mu m thick Sb2S3 absorber, double junction solar cells could achieve a theoretical efficiency as high as 26.64%. Our results based on the rotational design of bandgap alignment provide a general guide rule for selecting the optimal electron transport layer as well as the hole transport layer to boost the power conversion efficiency for Sb2S3 solar cells up to its theoretical limit.