Screen-printed conductive carbon layers for dye-sensitized solar cells and electrochemical detection of dopamine

In the field of printed electronics, carbon and its allotropes are today among the most studied materials due to their unique physical and chemical properties. In this work, carbon dispersions were used for the preparation of screen-printed carbon electrodes applied as counter electrodes (CEs) for the dye-sensitized solar cells and as working electrodes for electrochemical sensing. Following the simple and quick homogenization process, carbon dispersions were subjected to thermogravimetric analysis to closely examine drying, eventually sintering processes after printing. The influence of the graphite:carbon black ratio was investigated. The structure of composite carbon layers was analyzed by scanning electron microscopy and optical microscopy. The DSSC CEs printed from the dispersion containing 100 wt% of CB exhibited the highest catalytic activity for the effective reduction of oxidized triiodide I-3(-) back to iodide I- within the solar cell. The highest conversion efficiency achieved for the high-temperature processed CE was 3.05% with the fill factor of 0.65. The same composition of the carbon WE was used for the quantitative analysis of neurotransmitter dopamine. Based on the cyclic voltammetry measurements, the sensor showed a limit of detection of 13.3 nM for dopamine.