Influences of Precursor Solution Concentration and Temperature on CH₃NH₃PbI₃ Perovskite Layer Morphology and the Unconverted PbI₂ Proportion to their Perovskite Solar Cell Characteristics

Abstract

Abstract. The formation of organometal-halide perovskite crystal is simply based on stoichiometry reaction. However, the formation process seems to be sensitively affected by some process parameters such as concentration and temperature of precursor solution. In this work, we studied the formation of CH 3 NH 3 PbI 3 (MAPbI 3 ) crystal in mesoporous TiO 2 layer deposited by spin coating technique. Perovskite layers were characterized by X-Ray Diffraction (XRD) and its surface morphology were investigated by Scanning Electron Microscope (SEM). Perovskite layers obtained from precursor solution at 40°C and 60°C show a mesh-like structure. Meanwhile, for higher precursor solution temperature (80°C), it shows a flake-like structure. However, precursor solution at 60°C produced the best conversion of precursor solution with the smallest percentage of the remaining unconverted PbI 2 inside the produced crystal layer. These experimental results also showed that the best crystallization degree is obtained from 1.0 M precursor solution. The photovoltaic characteristics of their solar cells seem to have a correlation with the quantity of unconverted PbI 2 . High PbI 2 content significantly decreased the Filling Factor of the solar cell.

Impact of Dimensionality on Optoelectronic Properties of Hybrid Perovskites

“…From extrapolation of the linear part of the Tauc plot [33,34], the bandgap of (CH 3 NH 3 ) 2 Pb(SCN) 2 I 2 is estimated as 2.04 eV. This bandgap assignment of (CH 3 NH 3 ) 2 Pb(SCN) 2 I 2 is consistent with the reported values in the literature [21,26,30,33,35]. This bandgap is smaller than that of other typical single-layered Pb-I perovskites which is likely due to the reduced confinement of inorganic sheets that are induced by the shorter spacing and octahedral tilting in the inorganic sheets [36].…”

“…Morphology of prepared thin films was characterized using scanning electron microscopy (SEM). [27,30,31].…”

Cesium Lead Bromide Perovskites: Synthesis, Stability, and Photoluminescence Quantum Yield Enhancement by Hexadecyltrimethylammonium Bromide Doping

“…The formation of the perovskite depends strongly on the precursor’s concentration, temperature, environment, etc. 19 , 20 Thus, it is primarily essential to find the optimum route while synthesizing a perovskite, to acquire the best efficiency.…”

“…Despite the synthesis method adopted, controlling the process parameters such as concentration of precursors (Cs:Pb ratio), reaction time, and addition of solvents plays an essential role in the perovskites’ quality, crystallinity, crystal size, conversion of the precursor to the perovskite, and efficiency. The formation of the perovskite depends strongly on the precursor’s concentration, temperature, environment, etc. , Thus, it is primarily essential to find the optimum route while synthesizing a perovskite, to acquire the best efficiency.…”

Perovskite solar cells engineering and characterization

“…It's important to highlight here that the perovskite film's morphology, crystallinity and electronic characteristics are considerably sensitive to the processing conditions and parameters such as the precursor solution concentration and temperature [107,108], choice of solvent(s) [109], choice of the anti-solvent and its application rate [110,111], annealing temperature and time [21,22] and so on. As a result, various optimization strategies focusing on the deposition process were developed for both single and two-step methods in order to achieve a better control over the perovskite film quality and enhance the PSC performance.…”