LASER PATTERNING OF PEROVSKITE SOLAR CELLS: PROCESS DEVELOPMENT AND MINI-MODULE FABRICATION

摘要

Perovskite solar cells have been rapidly improved over the last years. At small lab-scale sizes efficiencies comparable to crystalline silicon solar cells were achieved. Successful up-scaling to large module sizes requires monolithic interconnection processes. Here we report on laser scribing processes of the P1, P2 and P3 patterning steps to interconnect perovskite solar cells. Particular emphasis is put on the P2 laser patterning step as it is known to induce detrimental material modifications of the absorber layer mostly at the bottom and in the vicinity of the scribed lines. Suitable process windows were established and optimized by systematic variation of the pulse length (ns, ps), wavelength (532 nm, 1064 nm) and the processing side (glass-/layer-side). By systematic analysis of the laser-matter interaction, the selective layer removal was achieved for all three patterning steps. The proper morphology and the electrical functionality, resulted in conditions for successful monolithic serial integration of a first three-cell perovskite mini-module with a power conversion efficiency above 10% and an interconnection width of 350 μm.