Stitching triple cation perovskite by a mixed anti-solvent process for high performance perovskite solar cells

Abstract

With the rapid development of organic-inorganic lead halide perovskite photovoltaics, increasingly more attentions are paid to explore the growth mechanism and precisely control the quality of perovskite films. In this study, we propose a "stitching effect" to fabricate high quality perovskite films by using chlorobenzene (CB) as an anti-solvent and isopropyl alcohol (IPA) as an additive into this anti-solvent. Because of the existence of IPA, CB can be efficiently released from the gaps of perovskite precursors and the perovskite film formation can be slightly modified in a controlled manner. More homogeneous surface morphology and larger grain size of perovskite films were achieved via this process. The reduced grain boundaries ensure low surface defect density and good carrier transport in the perovskite layer. Meanwhile, we also performed the Fourier transform infrared (FTIR) spectroscopy to investigate the film growth mechanism of unannealed and annealed perovskite films. Solar cells fabricated by using the "stitching effect" exhibited a best efficiency of 19.2%. Our results show that solvent and solvent additives dramatically influenced the formation and crystallization processes for perovskite materials due to their different coordination and extraction capabilities. This method presents a new path towards controlling the growth and morphology of perovskite films.

Highly Efficient and Stable MAPbI3 Perovskite Solar Cell Induced by Regulated Nucleation and Ostwald Recrystallization

“…The antisolvent treatment is effective in promoting the nucleation and producing compact film, which is successful in obtaining efficient perovskite solar cells. However, the grain size of perovskite film prepared with antisolvent treatment is small compared with the traditional method [21], owing to the accelerated nucleation. Accordingly, there exists more grain boundaries in the film, which are recombination centers deteriorating the photovoltaic performance of the solar cell.…”

Anti-Solvent Crystallization Strategies for Highly Efficient Perovskite Solar Cells

“…Certainly, these values were increased up to 16.5% when a solvent miscible with DMF (DE) was added in a 50-50 ratio [71]. Another interesting co-solvent system (6% IPA in CB) assisted to get an even higher PCE (19.2%) when dripped on a CsFAMA precursor perovskite film [72]. In the following Figure 12, we summarize all the PCEs attained using various anti-solvents in literature thus far.…”

Laser‐Generated Nanocrystals in Perovskite: Universal Embedding of Ligand‐Free and Sub‐10 nm Nanocrystals in Solution‐Processed Metal Halide Perovskite Films for Effectively Modulated Optoelectronic Performance

“…To achieve better control over the film morphology, various advanced processing approaches such as vacuum thermal evaporation, [12] sequential step deposition [13] and solvent-induced precipitation methods [14] have been developed. Various antisolvents such as toluene, [14] chlorobenzene, [15] chloroform, [16] diethyl ether, [17] ethyl acetate, [18] and even mixed antisolvent [19][20][21] have been explored to grow high quality perovskite films. Various antisolvents such as toluene, [14] chlorobenzene, [15] chloroform, [16] diethyl ether, [17] ethyl acetate, [18] and even mixed antisolvent [19][20][21] have been explored to grow high quality perovskite films.…”