Perovskite Based Solar Cells with Multi-Walled Carbon Nanotubes (MWCNTs)/Carbon Back Contact

The search for alternative energy solutions is currently a leading research area and will remain so for the foreseeable future, and photovoltaics (PV) are a key technology for a sustainable energy supply. The impressive properties of perovskites solar cells could ultimately boost efficiencies as close as commercial costly single-crystal silicon. That could make solar electricity as cheap as electricity produced from coal or natural gas. Solution base process of highly crystalline organic–inorganic hybrid perovskite CH₃NH₃PbI₃-_xCl_x pigment with promising visible-to-near-infrared absorptivity and electrical properties has attracted great attention to be used as a sensitizer for mesosuper structured solar cells.

In this work we fabricated cell structure of FTO/TiO₂/ CH₃NH₃PbI₃-_xCl_x/ MWCNTs-carbon as shown below in the schematic diagram (Figure 1). TiO₂ compact layer improved adhesion between the meso-TiO₂ layer and FTO surface to facilitate electron transfer and enhanced the efficiency of the photoelectrical conversion. Multi-walled carbon nanotubes/carbon paste back contact was used with polymeric binder. The output cell parameters achieved from current-voltage curve (Figure 2) were open circuit voltage of 0.72 V, short circuit current density of  11.62 mA/cm², fill factor of 0.27 and power conversion efficiency of 2.3%.