Eco‐Friendly Solvent Engineered CsPbI_2.77Br_0.23 Ink for Large‐Area and Scalable High Performance Perovskite Solar Cells

Abstract

The performance of large‐area perovskite solar cells (PSCs) has been assessed for typical compositions, such as methylammonium lead iodide (MAPbI3), using a blade coater, slot‐die coater, solution shearing, ink‐jet printing, and thermal evaporation. However, the fabrication of large‐area all‐inorganic perovskite films is not well developed. This study develops, for the first time, an eco‐friendly solvent engineered all‐inorganic perovskite ink of dimethyl sulfoxide (DMSO) as a main solvent with the addition of acetonitrile (ACN), 2‐methoxyethanol (2‐ME), or a mixture of ACN and 2‐ME to fabricate large‐area CsPbI2.77Br0.23 films with slot‐die coater at low temperatures (40–50 °C). The perovskite phase, morphology, defect density, and optoelectrical properties of prepared with different solvent ratios are thoroughly examined and they are correlated with their respective colloidal size distribution and solar cell performance. The optimized slot‐die‐coated CsPbI2.77Br0.23 perovskite film, which is prepared from the eco‐friendly binary solvents dimethyl sulfoxide:acetonitrile (0.8:0.2 v/v), demonstrates an impressive power conversion efficiency (PCE) of 19.05%. Moreover, the device maintains ≈91% of its original PCE after 1 month at 20% relative humidity in the dark. It is believed that this study will accelerate the reliable manufacturing of perovskite devices.

Printable thick junction-based lead-free perovskite single crystal powders for X-ray detection

“…The selection criteria for solvents capable of dissolving perovskites are based on the dielectric constant and Gutmann donor number. 25,26 The dielectric constant reflects the ability of a solvent to dissolve ionic compounds, while the Gutmann donor number describes the ability of a solvent to coordinate with cations. Solvents with a low Gutmann donor number would weakly coordinate with divalent metal centers and thus tend to form large molecular clusters.…”

[BMP]+[BF4]−-Modified CsPbI1.2Br1.8 Solar Cells with Improved Efficiency and Suppressed Photoinduced Phase Segregation

“…To address the issue of instability, it is suggested that the organic cations be replaced with all inorganic Cs + to create CsPbX 3 (X = I − , Br − , Cl − or their mixtures) [14][15][16][17][18]. CsPbX 3 typically has four types of crystal structures, including the cubic structure (α-, Pm3m), the tetragonal structure (β-, P4/mbm), the orthorhombic structure (γ-, Pbnm), and a nonperovskite structure (δ-, Pnma) [19].…”