Towards Stable Free Lead Mixed Halide Perovskite Thin Films on FTO-Coated Glass Substrate

Abstract All-inorganic cesium (Cs) lead perovskites have better thermal and chemical stability than organic–inorganic hybrids. They therefore represent a hope for increased performance of as absorber layers in photovoltaic solar cells. In the present work, we deposited different on FTO-coated glass substrates using one-step spin-coating method. The results substitution are presented critically discussed. X-ray diffraction (XRD) show four peaks all three samples. main films located at 2θ angles 26.45° 51.50° Muller indices (220) (242), respectively. These two indicate that prepared thin preferred crystallographic orientations. Beyond these peaks, other smaller 33.67° 37.70° corresponding to (210) (211), smoother surface films, more light they reflect, resulting poor absorption by films. It is important obtain image larger image, film. With this mind, carried out scanning electron microscope (SEM) analysis, which gave us images. Figure 3 shows SEM images CsPb 1− x Sn I 1.5 Br ( = 0, 0.5, 1) grown substrate with [Pb]/[Sn] ratios. As can be seen from figure, effect ratio visible smallest grain size unsubstituted CsPbI , while largest corresponds partially Pb-substituted layer (CsPb 0.5 ). fully (CsSnI ) has an intermediate size. surfaces well coated sizes vary greatly depending layer. best film partial Regarding UV-visible say absorb maximum amount wavelength range 350–550 nm. Above 550 nm, coefficients drop significantly. tin-free (Sn) remain higher throughout spectrum. degradation study revealed Sn-free retains good compared after 4 weeks exposure ambient environment. crystal structure resistance elements during weeks, shown renewed XRD exposure.