Effects of annealing temperature on photovoltaic properties of lead-free (CH₃NH₃)₃Bi₂I₉ solar cells

Abstract

Effects of annealing temperature on photovoltaic properties of lead-free (CH 3 NH 3 ) 3 Bi 2 I 9 solar cells were investigated. The (CH 3 NH 3 ) 3 Bi 2 I 9 photovoltaic cells were fabricated by a hot air blow-assisted spin-coating method. The spin-coated (CH 3 NH 3 ) 3 Bi 2 I 9 photoactive layers were annealed at temperatures of 100150 °C. Current densityvoltage characteristics of the (CH 3 NH 3 ) 3 Bi 2 I 9 photovoltaic cells showed that conversion efficiency increased with increasing annealing temperature. Microstructures and optical properties of the (CH 3 NH 3 ) 3 Bi 2 I 9 photoactive layers were also investigated by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and ultravioletvisiblenear infrared spectroscopy. The investigation revealed that the changes in lattice constants, crystallite size, surface morphology, and iodide/bismuth ratio of the (CH 3 NH 3 ) 3 Bi 2 I 9 were attributed to the annealing temperature, resulting in the changes in the photovoltaic properties of the (CH 3 NH 3 ) 3 Bi 2 I 9 solar cells.

Properties of ((CH3NH3)1-xCsx)3Bi2I9: (x=0-1.0) Hybrid Perovskite Solar Cells with Chlorobenzene Treatment

“…Our explanation agrees well with Mariyappan et al, who reported that the peaks intensity and the crystallinity corresponding to CB treated CBI perovskite were improved [3]. Furthermore, we calculate the crystallites size, D, of HPeSCs using the Scherrer equation [24] and it increases as CBI composition increased as shown in Figure 2(a). Likewise, the thickness of HPeSCs is increased as well as shown in Figure 2(b) and (c).…”

“…It can be observed that the main-phase peak of CBI at 25.14 o (00-6) 18) is increased in intensity as increasing the CBI composition except for x=0, which no CBI peak is observed. One peak of TiO 2 is observed at 25.37 o [23] and three of FTO peaks are observed at 26.82 o [24],…”

Annealing Time Dependence in the Fabrication of Bismuth-based Perovskite Solar Cells (Bi-PeSCs) by the Hot Immersion Method

“…Ataei et al [34], in 2021, fabricated MBI PeSCs by using the spin-coating method, but they suffered a non-uniformity surface morphology of MBI films, and the efficiency of the device was only 0.8%. While Shirahata et al [44] in 2020, employed the hot air blow technique. The researchers obtained highquality and rapidly crystallized MBI films; however, the morphology of the films was not uniform; it was rougher and not compact, and the efficiency was only 0.06% [44].…”

“…While Shirahata et al [44] in 2020, employed the hot air blow technique. The researchers obtained highquality and rapidly crystallized MBI films; however, the morphology of the films was not uniform; it was rougher and not compact, and the efficiency was only 0.06% [44]. In the same year, Momblona et al [5] fabricated MBI films through the thermal co-evaporation method and obtained an efficiency of 0.01%; however, the fabricated films were not smooth and had a rougher surface even after employing a complicated process.…”