Simple Method of Dual Passivation with Efficiency Beyond 20% for Fabricating Perovskite Solar Cells in the Full Ambient Air

Abstract

In order to further promote the commercial application of perovskite solar cells (PSCs), it is particularly important to fabricate devices in the ambient air condition. Herein, we explore a simple method to reproduce high-efficiency and stable PSCs using the one-step anti-solvent deposition conducted in the full ambient air. NH 4 Ac (ammonium acetate), which is green and environmentally friendly, is first introduced into an anti-solvent (ethyl acetate) to enhance the photovoltaic performance and stability of devices. NH 4 + causes the intermediate phase to undergo a process of cation exchange, thereby delaying crystallization. Ac − makes the additive and A-site cation form hydrogen bonds, which in turn makes the intermediate phase more stable. The dual effects of NH 4 + and Ac − delay the crystallization of the perovskite film, reduce the density of defect states, and decrease the non-radiative recombination of carriers. By optimizing the concentration of NH 4 Ac, a champion power conversion efficiency (PCE) of 20.41% and an average PCE of 19.46 ± 0.64% are achieved, which is currently one of the highest efficiencies in fabricating PSCs under the full ambient air condition. Furthermore, the corresponding PSCs without encapsulation can maintain 82% of its initial PCE when stored in full ambient air condition (30−40% RH) for 30 days.

Potassium Iodide-Modified Lead-Free Cs3Bi2I9 Perovskites for Enhanced High-Efficiency Solar Cells

“…This method was adopted from our previous work [ 14 ]; the fluorine-doped tin oxide (FTO) glass substrates were sequentially cleaned with acetone, isopropanol, anhydrous alcohol, and deionized water in a sequential ultrasonic cleaner for 15 min, followed by a 5 min plasma-cleaning treatment for 50 W.…”

“…Limiting ion transportation, passivating surfaces, adjusting compositions, and synthesizing low-dimensional perovskite materials are only some of the techniques employed to enhance long-term stability [ 12 , 13 , 14 ]. Substituting Pb 2+ with trivalent cations like Sn 2+ and Ge 2+ is the only proven method of eliminating Pb toxicity.…”

Organic–Inorganic Hybrid Electron Transport Layer for Rigid or Flexible Perovskite Solar Cells under Ambient Conditions

“…In order to make perovskite solar cells industrialized at low cost, our experiment will be carried out under ambient conditions. Many studies have also verified that PSCs with high performance can be prepared under ambient conditions. − Compared to pure SnO 2 colloid precursor, PVEM could effectively reduce the agglomeration of SnO 2 nanocrystals, while regulation and arrangement of SnO 2 nanocrystals on an ITO substrate can be obtained by coordination of PVEM. The resulting perovskite layer deposited on a PVEM–SnO 2 film exhibited a better vertically aligned crystal growth and higher quality.…”

Hydrogen Bond Network for Efficient and Stable Fully Ambient Air-Processed Perovskite Solar Cells with Over 21% Efficiency

“…In many existing studies on chemical passivation, the focus has largely been on the hydrogen bonds formed between passivating molecules and the surface of perovskite films. These bonds have been demonstrated to inhibit the migration of organic cations, thereby enhancing the stability of perovskite films. − However, the potential impact of hydrogen bonding between passivating molecules themselves has been largely overlooked. Theoretically, without altering the microstructure of the perovskite, such intermolecular hydrogen bonding could be even more effective in enhancing both the PCE and stability of the PSCs. , On the one hand, hydrogen bonding among the passivating molecules can create numerous carrier transport channels, structured as “perovskite-passivating molecule-perovskite”.…”