Abstract
Carbon dots (CDOTs) are increasingly becoming popular in the areas ranging from sensing and bioimaging to electronics. The interesting optical properties of CDOTs make it vital to explore its potential in the development of sustainable energy. In this work, one-step hydrothermally synthesized CDOTs were used as sensitizing agent in the fabrication of dye sensitized solar cell. The fabrication of the CDOT-based dye sensitized solar cell and its performance characteristics are explored in depth. The fabricated dye sensitized solar cell performance in terms of efficiency, voltage, and current was evaluated using a standard illumination of air-mass 1.5 global (AM 1.5 G) having an irradiance of 100 mW/cm [2]. The photon-to-current conversion efficiency (η) of only the carbon dot sensitized solar cell was 0.10% whereas the efficiency of the solar cell fabricated with a sensitizing dye made up of CDOT and N719 was 0.19%. As compared with the performance DSSCs fabricated with only 719 dye, it was observed that when CDOT was used in combination with N719 as sensitizing dye, the open circuit voltage increases yet the overall efficiency of the resulting solar cells decreases. It is clear from the result that CDOT could be used as a sensitizing dye in DSSCs. However, it is not very useful when used in combination with other sensitizing dyes due to energy transfer.
•Carbon dots (CDOTs) were uniquely and successfully synthesized and characterized.•Size analysis of the CDOT sensitized titanium dioxide was performed with TEM.•Energy transfer between N719 and CDOT was studied with Fluorescence Lifetime.•The current and voltage performance of CDOT sensitized solar cells was evaluated.