Tetramethylammonium based lead free perovskite active layer for solar cell application

Here we report the synthesis of a novel lead free organic-inorganic halide perovskite layer, tetramethylammonium tin tri-iodide (TMASnI(3)), by simple and cost-effective chemical synthesis technique. The microstructural and optical studies confirm the formation of hexagonal perovskite structure with optical band gap similar to 2.44 eV. A solar cell structure is fabricated by depositing the perovskite layer on zinc oxide thin film to demonstrate stable photovoltaic response under solar spectrum, where a thin layer of graphene oxide flakes on top of the perovskite layer acts as the charge transport layer. The open-circuit voltage (V-oc) and short circuit current density (J(sc)) for this cell as extracted from the current-voltage measurement under one sun illumination of AM1.5 solar radiation are 0.60 V and 8.65 mA/cm(2), respectively. Without using any conventional hole transport layer, the power conversion efficiency (eta) has been obtained as 1.92% which indicates the suitability of this perovskite material as an active layer for perovskite solar cell.