Lu Xiaoshuang, Xu Bin, Qin Xiatong, Chen Ye, Yang Pingxiong, Chu Junhao, Sun Lin
Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China.
National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China.
ACS Appl Mater Interfaces. 2020 Dec 30;12(52):58060-58071. doi: 10.1021/acsami.0c18799. Epub 2020 Dec 17.
The optimization of back contact interface is crucial to improve the performance of CuZnSnS (CZTS) thin film solar cells. In this paper, we first employ Al-doped ZnO (AZO) as the intermediate layer into the Mo/CZTS interface to improve the quality of back contact region. This AZO intermediate layer, obtained from the sputtering method prior to the CZTS precursor deposition, initially blocks the direct contact of CZTS with the Mo layer and thus indeed suppresses the decomposition reaction between Mo and CZTS. Consequently, the generation of voids at the back contact region is obviously avoided. Besides, the AZO intermediate layer can inhibit the reaction between sulfur (S) and Mo during sulfurization process, and thus significantly reduce the thickness of MoS. Meanwhile, the AZO intermediate layer with suitable thickness does not affect the crystal quality of CZTS absorber layer. Moreover, the effects of different thicknesses of predeposited AZO on the film morphology, composition, and corresponding device performance were systematically studied. After optimizing the thickness of the AZO layer, the efficiency of the resultant device has increased from 7.1% to 8.4% (the active area efficiency is 9.2%).
背接触界面的优化对于提高CuZnSnS（CZTS）薄膜太阳能电池的性能至关重要。在本文中，我们首先将Al掺杂的ZnO（AZO）作为中间层引入到Mo/CZTS界面中，以改善背接触区域的质量。这种AZO中间层是在沉积CZTS前驱体之前通过溅射法获得的，它首先阻止了CZTS与Mo层的直接接触，从而确实抑制了Mo与CZTS之间的分解反应。因此，明显避免了在背接触区域产生空洞。此外，AZO中间层可以抑制硫化过程中硫（S）与Mo之间的反应，从而显著降低MoS的厚度。同时，具有合适厚度的AZO中间层不会影响CZTS吸收层的晶体质量。此外，系统地研究了预沉积AZO的不同厚度对薄膜形态、成分以及相应器件性能的影响。优化AZO层的厚度后，所得器件的效率从7.1%提高到了8.4%（有源区效率为9.2%）。
