Synthesis of MAPbBr3-iYi (Y=I, Cl; i=0 ,1 ,2, 3) perovskite thin films

Abstract

[EN] Methylammonium lead halide perovskites with different halides (iodide, bromide and chloride) have been synthetized from methylamine, lead nitrate and the corresponding hydroX acid (X = I, Br, Cl) precursors. Subsequently MAPbBr3-iYi (Y= I, Cl; i=0, 1, 2, 3) perovskites were deposited as thin films onto FTO substrates by spin coating or dipping. Thin film perovskites were then characterized by X-Ray Diffraction, elemental analysis and optical spectrometry. Crystallites sizes are between 100-600 nm depending on the synthesis temperature. All synthetized MAPbX3-iYi perovskites crystallized in the same cubic phase irrespective of the X and Y components and a unique phase is observed. Elemental analy- sis shows that in all cases the atomic components meet the expected stoichiometric formulae. The bandgap of thin film MAPbX3-iYi perovskites were inferred from transmittance and reflectance spectral measurements. It is found that the on-set of the absorption edge for thin film MAPbX3 perovskites is about 1.66, 2.55 and 3.37 eV for X= I, Br, Cl, respectively "and it reaches intermediate values for mixed MAPbX3-iYi perovskites.