Abstract
Carbon-based electrodes represent a promising alternative to noble metals for fully printed flexible perovskite solar cells (FPSCs) due to their low cost, chemical stability, and compatibility with scalable manufacturing. In this work, the printing and optimization of carbon ink electrodes using slot-die coating and screen-printing techniques are systematically investigated for application in fully printed FPSCs. The influence of printing parameters on the electrical and structural properties of carbon films is evaluated through sheet resistance measurements and Raman spectroscopy. Slot-die-coated carbon electrodes deposited at an optimized pump rate of 1 mL min⁻¹ exhibit uniform films with a sheet resistance of approximately 80 Ω sq⁻¹, while screen printed electrodes fabricated using a multi point paste application strategy show improved uniformity with an average sheet resistance of ~125 Ω sq⁻¹. Using the optimized electrodes, fully printed FPSCs with a regular (n–i–p) architecture are fabricated on PET substrates. Devices incorporating slot-die coated carbon electrodes achieve a power conversion efficiency (PCE) of ~0.6% over a large active area, whereas screen printed carbon electrodes enable improved performance with a maximum PCE of 3.86%. These results demonstrate the feasibility of low-temperature, vacuum-free fabrication of flexible perovskite solar cells and provide practical guidelines for scalable roll-to-roll manufacturing. Key words: Printed perovskite solar cells; carbon electrodes; slot-die coating; screen printing; flexible electronics