A Nontoxic NFM Solvent for High-Efficiency Perovskite Solar Cells with a Widened Processing Window

Abstract

With the steady industrialization process of the perovskite solar cells (PSCs), the toxicity of the used solvents has become a pivotal issue that needs to be addressed. Especially, the usage of N,N-dimethylformamide (DMF) solvent would pose serious environmental and health concerns. Herein, we have reported a nontoxic solvent N-formylmorpholine (NFM) to replace the toxic DMF and have achieved a higher PCE of 22.78% compared to 21.97% when DMF was adopted. Moreover, with NFM, a widened antisolvent processing window was observed, facilitating the fabrication of PSCs with high reproducibility. This solvent engineering strategy offers an important solution to prepare eco-friendly, efficient, and stable perovskite solar cells.

Custom-tailored solvent engineering for efficient wide-bandgap perovskite solar cells with a wide processing window and low VOC losses

“…3h(i)), which is due to a slow evaporation rate and strong coordination capacity of PbI 2 and DMPU for obtaining a wider process window for crystal growth. 37,38 Mott-Schottky measurements were performed to investigate the origins of high V OC for the target PSCs (Fig. 4a).…”

Ameliorating the Interfacial Mismatch of SnO2 and Perovskite Enabling High Mechanical Stability for Flexible Perovskite Solar Cells

“…Among, the peak I around 530 eV and peak II at 531 eV are attributed to the lattice oxygen (O lattice ) and surface defect oxygen (O defect ) of SnO 2 , separately, while the peak III, located at 533.8 eV, is coming from the surface oxygen in PDA (Figure S6b, Supporting Information). [ 42 ] As the Gaussian fitting results show in Table S2, Supporting Information, the ratio of O defect for PDA: SnO 2 is 20.19%, much less than that for SnO 2 film (38.46%), indicating that the PDA modification could benefit the charge transfer process since O defect acts as the charge recombination center. [ 43 ]…”

Co‐Solvent Engineering Contributing to Achieve High‐Performance Perovskite Solar Cells and Modules Based on Anti‐Solvent Free Technology

“…Meanwhile, it is easy to evaporate and leads to great damages for environment. [ 12,14 ] Therefore, it is still a big challenge to realize large‐scale commercial application of PSCs via anti‐solvent assisted crystallization strategy. [ 15,16 ]…”

“…Meanwhile, it is easy to evaporate and leads to great damages for environment. [12,14] Therefore, it is still a big challenge to realize largescale commercial application of PSCs via anti-solvent assisted crystallization strategy. [15,16] The purpose of using anti-solvent is to create an instantaneous local supersaturation surroundings during spinning, then nucleation occurs when concentration of liquid film is higher than critical concentration of nuclei according to LaMer model.…”

“…First, the process conditions always need to be accurately controlled, not only the amount of solution, but also the dropping time of anti-solvent. [11][12][13] Moreover, most of anti-solvents are toxic and harmful to creatures. Meanwhile, it is easy to evaporate and leads to great damages for environment.…”