The dye sensitized solar cells were fabricated by using TiO2 as photoanode material and N3 dye as sensitizer also another solar cell was fabricated by using ZnO as photoanode material same dye , electrolyte and counter electrode. why does the conversion efficiency of TiO2 is higher than the ZnO?
Dear Niyamat,
welcome,
There are two factors which are distinguishing the electron transport layers in the DSSC:
- the matching of the energy bands of the electron transport layer with the active die where the condition band edge of the etl must slightly be lower than the lumo level of the die and its valence band edge much lower than that of the Die. By inspecting the energy level diagram of the two solar cell types you find a better matching for TiO2 than ZO.
The other factor is porosity of the film. It is so as the material is more porous it will be more suitable for increasing the light path absorbing more photons of the incident light.
If you display the open circuit voltage ans the shortcircuit current in both cases one can verify the effect of the two factors. It is so that the the second factor affect more the the shortcircuit current.
While the first factor may affect both the opencircuit voltage and the shortcircuit current.
Best wishes
- Badges
- Science topic