Muzzillo Christopher P, Reese Matthew O, Mansfield Lorelle M
National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401, United States.
Langmuir. 2020 May 5;36(17):4630-4636. doi: 10.1021/acs.langmuir.0c00276. Epub 2020 Apr 21.
The fundamentals of using cracked film lithography (CFL) to fabricate metal grids for transparent contacts in solar cells were studied. The underlying physics of drying-induced cracks were well-predicted by an empirical correlation relating crack spacing to capillary pressure. CFL is primarily controlled by varying the crack template thickness, which establishes a three-way tradeoff between the areal density of cracks, crack width, and spacing between cracks, which in turn determine final grid transmittance, grid sheet resistance, and the semiconductor resistance for a given solar cell. Since CFL uses a lift-off process, an additional constraint is that the metal thickness must be less than 1/3 of the crack template thickness. The transmittance/grid sheet resistance/wire spacing tradeoffs measured in this work were used to calculate solar cell performance: CFL-patterned grids should outperform screen-printed grids for narrow cells (0.5-2 cm wide) and/or cells with high semiconductor sheet resistance (≥100 Ω/sq), making CFL attractive for monolithically integrated thin-film photovoltaic modules.
研究了使用裂纹膜光刻（CFL）技术制造用于太阳能电池透明接触的金属网格的基本原理。通过将裂纹间距与毛细管压力相关联的经验关联式，可以很好地预测干燥诱导裂纹的基本物理过程。CFL主要通过改变裂纹模板厚度来控制，这在裂纹的面密度、裂纹宽度和裂纹间距之间建立了三方权衡，进而决定了给定太阳能电池的最终网格透过率、网格薄层电阻和半导体电阻。由于CFL使用剥离工艺，另一个限制是金属厚度必须小于裂纹模板厚度的1/3。在这项工作中测量的透过率/网格薄层电阻/线间距权衡用于计算太阳能电池性能：对于窄电池（0.5 - 2厘米宽）和/或具有高半导体薄层电阻（≥100Ω/sq）的电池，CFL图案化网格应优于丝网印刷网格，这使得CFL对于单片集成薄膜光伏模块具有吸引力。
