Fabrication and investigation of a new highly humidity stable nanocrystalline perovskite, tetramethylammonium lead triiodide to be used in solar cells

Hybrid organic-inorganic halide perovskite (CH3NH3PbI3) materials have broad applications such as photovoltaics, light emitting diodes, and sensors. However, one of the major drawbacks of these materials is their sensitivity to moisture. Here, a new promising perovskite nanocrystal: tetramethylammonium lead triiodide (CH3)4NPbI3 has been introduced and fabricated. Investigation of morphology, structural, optical and stability properties was done by XRD, SEM, TEM, and UV-visible. Characterization prove that the processed powder is in the form of nanoparticles and drop cast film has a hexagonal rod-like morphology. Crystal structure was determined by powder x-ray diffraction and electron diffraction pattern. It shows a perovskite crystal structure with a hexagonal unit cell. Powder XRD after 45 days suggests that this new compound is stable in humid conditions. Direct optical band gap of this material was obtained by transforming diffuse reflectance spectrum to Kubelka-Munk spectrum and it was 2.66 eV.