Hatt Thibaud, Bartsch Jonas, Davis Victoria, Richter Armin, Kluska Sven, Glunz Stefan W, Glatthaar Markus, Fischer Anna
Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg, Germany.
Institute of Inorganic and Analytical Chemistry, University of Freiburg, Albertstraße 21, 79104 Freiburg, Germany.
ACS Appl Mater Interfaces. 2021 Feb 3;13(4):5803-5813. doi: 10.1021/acsami.0c20134. Epub 2021 Jan 25.
A resist-free metallization of copper-plated contacts is attractive to replace screen-printed silver contacts and is demonstrated on large-area silicon heterojunction (SHJ) solar cells. In our approach, a self-passivated Al layer is used as a mask during the plating process. In this study, Al/AlO or AlO plating masks are further functionalized by a self-assembled monolayer (SAM) of octadecyl phosphonic acid (ODPA). The ODPA adsorption is characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy in attenuated total reflectance (FTIR-ATR) (in situ), and contact angle measurements to link the surface chemical composition to wetting properties. The SAM leads to homogeneous hydrophobic surfaces on large-area textured solar cells and planar flexible printed circuit boards (PCBs), which allows reproducible patterning of narrow lines by inkjet printing of an etchant. Selective copper plating is then performed to complete the metallization process and produce Cu contacts in the patterned areas. Silicon heterojunction (SHJ) solar cells metallized by the complete sequence reached up to 22.4% efficiency on a large area.
用于镀铜触点的无抗蚀剂金属化工艺对于替代丝网印刷银触点具有吸引力，并已在大面积硅异质结（SHJ）太阳能电池上得到验证。在我们的方法中，在电镀过程中使用自钝化铝层作为掩膜。在本研究中，Al/AlO或AlO电镀掩膜通过十八烷基膦酸（ODPA）的自组装单分子层（SAM）进一步功能化。通过X射线光电子能谱（XPS）、衰减全反射傅里叶变换红外光谱（FTIR-ATR）（原位）和接触角测量对ODPA吸附进行表征，以将表面化学成分与润湿性联系起来。该自组装单分子层在大面积纹理化太阳能电池和平面柔性印刷电路板（PCB）上形成均匀的疏水表面，这使得通过喷墨打印蚀刻剂实现窄线的可重复图案化成为可能。然后进行选择性镀铜以完成金属化过程，并在图案化区域产生铜触点。通过完整工艺序列金属化的硅异质结（SHJ）太阳能电池在大面积上的效率达到了22.4%。
