Heterostructured CoTe2/g-C3N4 nanocomposite thin film counters electrodes for enhancing the photovoltaic performance of dye-sensitized solar cells

In this study, dye-sensitized solar cells (DSSCs) were created by using CoTe2 modified g-C3N4 nanosheets as counter electrode materials. CoTe2 has an orthorhombic crystalline structure (JCPDS No. 74-0245) and independent spherical shaped morphology sizes in the range of 25–35 nm, which is further distributed evenly on the surface of g-C3N4 in the CoTe2/g-C3N4 composite films, according to XRD and TEM results. UV and PL spectroscopic experiments were used to examine the optical band gap and charge transfer utilization of the fabricated films. The experimental results demonstrated that after being modified with g-C3N4, the photoelectric conversion efficiency of DSSCs was clearly improved. The DSSC with 5 wt% CoTe2 incorporated g-C3N4 CE exhibits high PCE of 7.41 %, which is 2.1 times better than that of bare CoTe2 (3.89 %). Moreover, the CoTe2/g-C3N4 showed high electrocatalytic activity and longer electron life time, which is confirmed by CV, EIS and Tafel polarization experimental studies. [Display omitted] •CoTe2 modified g-C3N4 nanosheets CEs was used in DSSCs.•The DSSC with 5-CoTe2/g-C3N4 CE showed PCE of 8.12 %, which is 2.1 times better than that of bare CoTe2 (4.06 %).•CoTe2/g-C3N4 showed high electrocatalytic activity and longer electron life time.