Preparation of highly efficient carbon-based perovskite solar cells (C-based PSCs) by screen-printing

Halide perovskite solar cells (PSCs) have increased their power energy conversion efficiency (PCEs) drastically in the last few years, becoming one of the most competitive photovoltaic technologies. However, instability problems and materials toxicity are two of the most important drawbacks that delays its commercialization. Different strategies have been proposed in order to increase the operational stability of the devices. One of these approaches is the replacement of the unstable hole transport layer (Spiro-OMeTAD) or the improvement of the stability to moisture through the application of semiconductor oxides as transport layers or scaffolds. In this respect, the carbon-based perovskite solar cells (C-PSCs) applies bilayer electrode made of the mesoporous TiO2 (m-TiO2), as the electron transport layer, and the mesoporous ZrO2 (m-ZrO2) used as scaffold. In this PSC configuration the application of a hole transport layer as well as the application of a back-metal electrode (e.g. Au) is avoided and replaced by a highly conductive porous carbon electrode. The final triple-layer TiO2/ZrO2/carbon is applied to fabricate printable mesoscopic solar cells, where the metal halide perovskite solution is infiltrated within the porous TiO2/ZrO2 bilayer and through the printed carbon layer. In this work, we present our most recent results on the application and optimization of C-based PSCs with champion PSCs efficiencies of similar to 14 %.