Lignite derived nanocarbon as surface passivator and co-sensitizer in DSSC

Interfacial exciton recombination and narrow absorption region are two bottlenecks that limit the performance of a DSSC. The present study focuses on improving the solar cell’s efficiency by utilizing a lignite-derived nanocarbon that behaves as a surface passivator and co-sensitizer. Incorporating nanocarbon enhanced the spectral absorption region of N719 dye with a bathochromic shift and played the role of a co-sensitizer. In addition, the quenched PL spectra revealed that nanocarbon also aids in the swift transfer of electrons to the conduction band of TiO by reducing the exciton recombination and acting as a surface passivator. On measuring the fabricated DSSC under AM 1.5G irradiation with the intensity of 100 mWcm, the nanocarbon-based device exhibited an efficiency (ŋ) of 9.02% with a photocurrent density of 20.45 mAcm, outperforming the pristine device (ŋ = 6.21%). An enhancement of 45% in the PCE was achieved. Thus, the results unveiled that nanocarbons derived from pollution-causing fuel synergistically aided in enhancing the performance of DSSC.