Carbon-based perovskite solar cell

During the last ten years perovskite solar cell (PSC) technology gained the world scientific interest because of some peculiar features as the high absorption coefficient and the carrier transportation that permit to reach efficiencies about 26%. A typical PSC can be obtained by a n-i-p junction where the perovskite is the intrinsic semiconductor sandwiched between a p-type (HTM, Hole Transporting Material) and n-type (ETM, Electron Transporting Material) semiconductor. The HTM is the main source of instability within the solar cell stack. In the standard structure, on top of the HTM a metal counter-electrode is thermally evaporated. Gold is the most used counter-electrode for high efficiency cells, but it is corroded by halogen ions expensive. For these reasons, the HTM and the metal top-electrode can be replaced by a cheap low temperature firing carbon black/graphite layer. Carbon-based perovskite solar cells (C-PSCs) are a cell concept introduced to address the issues of instability, manufacturing complexity and high costs. Low temperature (T<100°) carbon-based electrodes have been widely applied in perovskite solar cells because of their chemical inertness and compatibility with up-scalable techniques, signifying their solid potential for mass-production. If the low-cost perspective is achieved through the carbon electrode that avoid high-vacuum thermal evaporation of gold electrode, there is still a lack of efficiency for this type of PSCs. In this work we optimized the low temperature carbon based cell structure by blade-coating a carbon-based ink as counter-electrode.