Preparation of CsPbBr₃ Films for Efficient Perovskite Solar Cells from Aqueous Solutions

Abstract

Toxic organic solvents are widely used in fabricating perovskite solar cells, which pose a potential threat to human health and the environment. Here, we try to prepare high-quality all-inorganic perovskite films from all aqueous solutions using a traditional two-step method. A continuous PbBr2 precursor film is first prepared from a HBr/H2O solution added with a certain amount of poly­(ethylene glycol) (PEG). The PEG plays important roles in adjusting the viscosity of the aqueous solution and affecting the growth of the PbBr2 precursor crystals. A high concentration of the CsBr/H2O solution is then spin-coated on the PbBr2 precursor film followed by annealing to form a high-quality CsPbBr3 film. The CsPbBr3 perovskite solar cells prepared from the aqueous solutions show an efficiency of 7.19%, which is higher than those prepared from the organic solvents in the same conditions. It is a facile and green method to eliminate the solvent toxicity derived from organic solvents in fabricating perovskite solar cells.

Crystallization Regulation and Dual‐Defects Healing by Self‐Polymerization of Multifunctional Monomer Additives for Stable and Efficient CsPbBr3 Perovskite Solar Cells

“…[ 16 ] However, due to the too fast crystallization, CsPbBr 3 film prepared by this simple two‐step method also contains a mass of defects located on the numerous grain boundaries, which behave as nonradiative recombination centers for photogenerated carriers to seriously deteriorate the PCE and stability of devices. [ 17–19 ]…”

“…[16] However, due to the too fast crystallization, CsPbBr 3 film prepared by this simple two-step method also contains a mass of defects located on the numerous grain boundaries, which behave as nonradiative recombination centers for photogenerated carriers to seriously deteriorate the PCE and stability of devices. [17][18][19] Additive engineering has been widely employed to both regulate the crystallization kinetics to improve the perovskite film quality and to passivate the grain boundaries defects. [20] In particular, organic additives with a multitude of chemical functionalities present salient superiority, for example, the commonly used Lewis base organic small molecules such as urea (O-donor), thiophene (S-donor), and pyridine (N-donor) can combine with perovskite precursors through Lewis acid-base interaction to retard the nucleation and grain growth and heal metal ions defects to fabricate a large-grained perovskite film with reduced imperfections.…”

Research Progress of Green Solvent in CsPbBr3 Perovskite Solar Cells

“…Wei’s group adopted all-aqueous solutions to prepare all-inorganic CsPbBr 3 perovskite films, in which the HBr/H 2 O solution containing a small amount of poly (ethylene glycol) (PEG) was used to dissolve PbBr 2 and H 2 O to dissolve CsBr, as shown in Figure 13 . The CsPbBr 3 PSCs prepared in this way show a PCE of 7.19%, and the PCE of PSC maintains a maximum PCE of 95.8% after 22 days [ 66 ]. These efforts make it possible to fabricate perovskite films using all aqueous solutions.…”

Interface properties of CsPbBr$_3$ /CsPbI$_3$ perovskite heterostructure for solar cell

“…But, the metal halide perovskites (MHPs) is a subject of increasing interest because of its marvellous photophysical properties [25]. Especially, the inorganic hybrid perovskite solar cells such as CsPbBr 3 and CsPbI 3 are more stable to moisture, heat and light exposure with high power conversion efficiency [26,27].…”