Insertion of the AGS layer at the CIGSe/ITO interface: A way to reduce the formation of the GaOx interfacial phase in CIGSe solar cells
Insertion of the AGS layer at the CIGSe/ITO interface: A way to reduce the formation of the GaOx interfacial phase in CIGSe solar cells
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DOI：
10.1016/j.solmat.2017.12.020
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发表时间：
2018-05
影响因子：
6.9
通讯作者：
Muhammad Saifullah;Kihwan Kim;Rauf Shahzad;J. Gwak;J. Cho;J. Yoo;J. Yun;Joo Hyung Park
中科院分区：
文献类型：
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作者：
Muhammad Saifullah;Kihwan Kim;Rauf Shahzad;J. Gwak;J. Cho;J. Yoo;J. Yun;Joo Hyung Park
在锡掺杂氧化铟 (ITO) 背电极上制备了基于带隙约为 1.5 eV 的超薄吸收体的半透明 (ST) Cu(In,Ga)Se2(CIGSe) 太阳能电池。在吸收层厚度≤300 nm 的太阳能电池中，在 CIGSe 层和 ITO 背接触之间加入硫化 AgGa (AGS) 层可以提高器件效率。本文探讨了 AGS 层对 CIGSe 结构和 CIGSe/ITO 界面的影响。同时，在AGS层间-CIGSe吸收体中观察到有序缺陷化合物的形成，其根源是由于In从ITO扩散到吸收体而引起的(Ag+Cu)/(Ga+In)比率的降低以及AGS层中Ag/Ga比率为0.60。研究发现AGS层可以显着减少CIGSe/ITO界面处GaOx相的形成。然而，AGS 层间吸收体中 CIGSe 层沉积时间的增加导致 GaOx 界面 (IF) 层厚度的增加。当 GaOxIF 层厚度增加时，基于 AGS 层间吸收体的器件的照明 J-V 曲线中的翻转现象变得越来越明显。 SCAPS（太阳能电池电容模拟器）模拟结果表明，具有AGS层的太阳能电池的照明J-V曲线中出现翻转效应的原因是GaOxIF相（本质上是n型）。根据目前的结果，还讨论了进一步提高 ST CIGSe 太阳能电池转换效率的可能性。
Semitransparent (ST) Cu(In,Ga)Se2(CIGSe) solar cells based on the ultrathin absorbers with a bandgap of ~1.5 eV are prepared on the tin-doped indium oxide (ITO) back electrode. In a solar cell with absorber thickness ≤300 nm, incorporation of a sulfurized-AgGa (AGS) layer between the CIGSe layer and the ITO back contact was found to improve the device efficiency. This article explores the effect of the AGS layer on the CIGSe structure and CIGSe/ITO interface. Meanwhile, an ordered defect compound formation is observed in the AGS interlayered-CIGSe absorbers, the origin of which is the decrease in the (Ag+Cu)/(Ga+In) ratio arising from diffusion of In from the ITO to the absorber and the Ag/Ga ratio of 0.60 in the AGS layer. It is found that the AGS layer can significantly reduce the formation of the GaOxphase at the CIGSe/ITO interface. However, the increase in the deposition time of the CIGSe layer in the AGS interlayered-absorbers resulted in an increase in the GaOxinterfacial (IF) layer thickness. The roll-over phenomenon in the illuminated J-V curves of devices based on AGS interlayered-absorbers became increasingly pronounced when the thickness of GaOxIF layer increased. The SCAPS (solar cell capacitance simulator) simulation results indicate that the reason for the roll-over effect in the illuminated J-V curves of the solar cells with AGS layers is the GaOxIF phase (n-type in nature). In light of the present results, possibilities to further enhance the conversion efficiency of ST CIGSe solar cells are also discussed.