Insights into the interplay of different recombination mechanisms and their origins (bulk, surface) are provided comparing fresh, light-soaked and aged devices.

Apart from the high power conversion efficiencies (PCEs), [1][2][3] one of the most attractive features of ABX 3 (A = Cs, methylammonium (MA), and formamidinium (FA); B = Pb and Sn; and X = Cl, Br, and I) perovskites is the simplicity of fabrication. Perovskite thin films can be deposited through a variety of different techniques ranging from one-step [4][5][6][7][8] and two-step sequential methods, [9][10][11] vaporassisted solution processing, [12,13] and thermal gas-assisted evaporation. [9,[14][15][16][17][18] However, in a laboratory setting, one-step spin-coating remains the simplest and quickest route for high-quality perovskite layers. To improve film morphology, the spin-coating deposition has been optimized using solvent mixtures (e.g., dimethylformamide (DMF), dimethylsulfoxide (DMSO), γ-butyrolactone (GBL)), [19] and a variety of lead salt precursors. [20][21][22] Importantly, almost all currently reported All current highest efficiency perovskite solar cells (PSCs) use highly toxic, halogenated solvents, such as chlorobenzene (CB) or toluene (TLN), in an antisolvent step or as solvent for the hole transporter material (HTM). A more environmentally friendly antisolvent is highly desirable for decreasing chronic health risk. Here, the efficacy of anisole (ANS), as a greener antisolvent for highest efficiency PSCs, is investigated. The fabrication inside and outside of the glovebox showing high power conversion efficiencies of 19.9% and 15.5%, respectively. Importantly, a fully nonhalogenated solvent system is demonstrated where ANS is used as both the antisolvent and the solvent for the HTM. With this, state-of-the-art efficiencies close to 20.5%, the highest to date without using toxic CB or TLN, are reached. Through scanning electron microscopy, UV-vis, photoluminescence, and X-ray diffraction, it is shown that ANS results in similar mixed-ion perovskite films under glovebox atmosphere as CB and TLN. This underlines that ANS is indeed a viable green solvent system for PSCs and should urgently be adopted by labs and companies to avoid systematic health risks for researchers and employees.

Experimental and theoretical study on the effect of shallow and deep defects on photovoltaic performance, luminescence, surface photovoltage, and density of states.