Effect of TiO2 scatterer on photovoltaic performance of quantum dot solar cell

Quantum dot solar cells (QDSCs) are emerged as an advanced alternate to dye sensitized solar cells due to appealing properties of quantum dots like size tuneable band gap, multiple exciton generation, large extinction coefficient and intrinsic dipole moment. Keeping this in mind CdS based QDSCs are fabricated with ZnS as passivation layer using simple and economic SILAR technique. Design of photoanode is a key factor to improve the photovoltaic performance of QDSC by enhanced light harvesting. To improve the light absorption in QDSC and hence the photovoltaic parameters, photoanode with doctor bladed larger sized TiO₂ nanoparticle paste as scattering layer is fabricated. A sharp increase in short circuit current density along with improved open circuit voltage and fill factor is observed which leads to 47% increase in photo conversion efficiency. Further, electrochemical impedance spectroscopy (EIS) is studied to examine the interfacial charge transfer in the QDSCs.