Highly effective Pt-free counter electrode constructed by break bone-like CoTe@graphite carbon thin films dye-synthesized solar cell

Abstract

To boost the efficiency of dye-sensitized solar cells (DSSCs) at a cheaper cost than currently available counter electrodes, platinum (Pt)-based CEs are necessary. We demonstrate the creation of thin films with different aspect ratios made of molybdenum ditelluride (CoTe) combined with graphitic carbon nitrides (g-C3N4) using the chemical vapour deposition technique on an FTO glass substrate. According to XRD, Raman, SEM, and TEM examination, the 2D nanosheets of g-C3N4have a polycrystalline nature and uniform nanograins that break human bone like the morphology of CoTe. The optical band gap and charge transfer efficiency of the films was assessed using UV and PL spectroscopy. In experiments, the modification of DSSCs with g-C3N4 significantly increased their photoelectric conversion efficiency. The DSSC incorporating CoTe@g-C3N4CE achieved high-power conversion efficiency (PCE) of 8.52% compared to DSSC with bare CoTe CE (2.67%).Furthermore, the upgraded CoTe@g-C3N4CE exhibited improved electron lifetime compared to other CEs, significant reduction towards I3-, and good electrocatalytic activity. Additionally, CoTe@g-C3N4 shows excellent electrocatalytic activity and prolonged electron lifetime, which is supported by experimental work using Tafel polarisation, EIS, and CV.