Enhance the performance of dye-sensitized solar cells by Bi2Te3 nanosheet/ZnO nanoparticle composite photoanode

Hexagonal Bi 2 Te 3 nanosheets with uniform morphology were facilely synthesized through a hydrothermal method at 180 °C. X ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and selected area electron diffraction (SAED) were employed to characterize the Bi 2 Te 3 nanosheets . The results clearly indicate that uniform Bi 2 Te 3 nanosheets with a side length of 300–400 nm were obtained. Bi 2 Te 3 nanosheet/ZnO nanoparticle (Bi 2 Te 3 NS/ZnO NP) composite photoanodes were fabricated with Bi 2 Te 3 NS concentration in the range of 0–0.25 at.%. The effect of Bi 2 Te 3 NS contents in composite photoanode on the performance of dye-sensitized solar cells (DSSCs) was systematically investigated. The photocurrent density-voltage ( J-V ) characteristics indicate that the DSSCs with Bi 2 Te 3 NS/ZnO NP composite photoanode exhibit significantly improved photovoltaic performance . Typically, the highest energy conversion efficiency of 4.10% which is increased by 46.95% compared with that of the bare ZnO can be achieved in the DSSC with 0.15 at.% Bi 2 Te 3 NS embedding. The EIS results further confirm that a moderate amount of Bi 2 Te 3 NS in photoanode could not only improve the electrons transport and suppress the charge recombination rate, but also enhance the electron collection efficiency. Furthermore, the excellent thermoelectric performance of Bi 2 Te 3 NS in the photoanode could greatly increase the electron density and lower the temperature of the DSSCs effectively. All these results suggest that the Bi 2 Te 3 NS/ZnO NP composite photoanode could highly enhance the performance of the DSSCs.