Fabrication of back-contact electrodes using modified natural lithography

The fabrication of back-contact electrodes with micron-sized features by microsphere lithography is implemented via a modified "natural lithography" approach. The solution-based assembly of microsphere beads on a substrate occurs via the electrostatic attraction between the molecular monolayer-functionalized substrate and the micron-sized polystyrene microbeads with carboxyl surface groups. Through a modification of the original "natural lithography" method, the density of the microbeads used as a lithographic mask can be increased 5-fold. The resulting back-contact electrodes are used for the fabrication of perovskite solar cell devices and the examination of their potential. Devices with electrodes fabricated using a modified "natural lithography" approach showed a 3.5-fold increase in performance compared to the devices with electrodes made using the original method.