Investigation of electron transfer properties of nitrogen-doped carbon dots obtained from a dialysis-free approach

National Centre for Ultrafast Processes, University of Madras, Taramani Campus, Chennai-600 113, India Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai-600 025, India E-mail: prm60@hotmail.com Manuscript received online 28 November 2018, accepted 11 December 2018 Carbon dots (CDs) are widely used as a solar energy material in the current scenario. N-CDs-based dye sensitized solar cell (DSSC) device exhibited the best power conversion efficiency (PCE) so far. We hope a DSSC device based on covalently linked N-CDs with organic dyes may increase the efficiency of solar cells by blocking recombination effectively. As a preliminary study, before enter into the device fabrication, we have investigated the electron transfer behaviour of N-CDs in solution state in the presence of DMA and MV2+. We have synthesized the N-CDs from glycine by a simple dialysis-free approach. The resulting N-CDs exhibit luminescence quantum yield of 33.1%. The luminescence of N-CDs is effectively quenched by DMA and MV2+. Detailed investigation revealed that the quenching is caused by a dynamic photoinduced electron transfer mechanism and the bimolecular quenching constant values are 8.5×109 M–1 s–1 and 6.9×109 M–1 s–1 respectively for DMA and MV2+