Influence of laser fluence and pulse duration on patterning of perovskite solar cells: An analysis of optoelectronic and electrical parameters by hyperspectral photoluminescence imaging

Up-scaling of perovskite solar cells and modules requires both the development of suitable laser patterning processes for series interconnection of the cells and the quantification of the spatial distribution of solar cell parameters. Here, we investigate perovskite solar cells patterned with ns and ps laser pulses at varying laser fluences and analyze them with hyperspectral photoluminescence (PL) imaging. Based on these images, mappings of the distribution of the central PL wavelength, the quasi-Fermi-level splitting, the Urbach energy and the shunt resistance were calculated. From the behavior of these parameters, particularly in the vicinity of the laser trenches, we infer laser-material interaction processes and their influence on the electrical performance of the interconnected cells. It is shown that both ps and ns laser pulses can be used for successful series interconnection with low electrical losses in a very narrow edge regions, provided that the fluence is carefully adjusted.