1T and 2H phase molybdenum disulfide as a counter electrode for Pt free dye-sensitized solar cells

Thin films of 1T and 2H mixed-phase MoS2 on FTO substrate by hydrothermal technique with altering reaction time (24 (12) 60 h) was made. Raman and XRD analysis confirm the coexistence of 2H and 1T phase of MoS2. Transformation of nanoplatelets into nanobelts with reaction time was witnessed in SEM and UV-Vis-NIR absorbance pattern shows characteristic absorption peaks of MoS2 at 291 nm and 680 nm. Due to the change in morphology, the bandgap of MoS2 increased from 1.82 eV (nanoplatelets) to 1.97 eV (nanobelts). Fabrication of MoS2 CE based DSSCs with assembly of (TiO2/N719/I3-I-/MoS2) was made and photoconversion efficiency follows the order MoS2-36 > MoS2-24 > MoS2-48 > MoS2-60. MoS2-36 electrode (7.96 %) based DSSC exhibits higher photoconversion efficiency than Pt (6.8 %) based DSSC. Thus, mixed-phase of MoS2 nanobelts stand superior and can be used as a potential candidate for counter electrodes compared to cost-effective Pt free DSSC.

Automated summary

Thin films of mixed-phase 1T and 2H MoS2 on FTO substrate were prepared using hydrothermal technique, and the morphology and bandgap of the films could be controlled by altering reaction time. The MoS2-36 electrode exhibited higher photoconversion efficiency in DSSCs compared to Pt-based DSSCs.