Organic-inorganic lead halide perovskite solar cells (PSCs) belonging to thin-film solar cells, have gained much attraction due to their low cost, high molar extinction coefficients and excellent charge carrier mobility. Currently a highest efficiency of 25.7% is reported for solar cells employing these hybrid perovskite light harvester materials. The major problem in many of the reported high efficiency PSCs arises from the use of organic hole transport layers such as Spiro–OMeTAD or PEDOT: PSS, which are unstable in the ambient air. To overcome these challenges, PSCs fabrication is reported with the carbon-based whole mesostructured architecture, where carbon layer acts as moisture barrier and prevents the hydration of the infiltrated perovskite thus substantially reduces the degradation kinetics.