Performance and Stability Improvement of Inverted Perovskite Solar Cells by Interface Modification of Charge Transport Layers Using an Azulene–Pyridine Molecule

Abstract

Herein, an azulene–pyridine molecule (AzPy) is implemented in inverted perovskite solar cells (PSCs) for increasing the power conversion efficiency (PCE) and the stability of the devices. The first goal is achieved by depositing a thin layer of AzPy on top of the hole charge transport layer (HTL). The surface engineering of HTL with AzPy improves the perovskite layer formation, thus increasing light absorption and reducing bulk nonradiative recombination while protecting the perovskite from degradation species from the HTL. This approach increases the mean PCE by approximately 6%. The second goal of improving the stability of the devices is mainly achieved by replacing the hydrophilic bathocuproine (BCP) with the more hydrophobic AzPy. By the development of an AzPy layer over the electron transport layer (ETL), the stability of the PSCs is increased under ambient conditions and thermal or light stress, without affecting the PCE. The two proposed interface engineering approaches are both implemented in the device in conjunction with the perovskite surface treatment with n‐hexylammonium bromide, resulting in devices that deliver a PCE of 20.42% and increased thermal and light stability, thus retaining 90% of their initial PCE for more than 1200 h under ambient conditions.

Engineering of the perovskite/electron-transporting layer interface with transition metal chalcogenides for improving the performance of inverted perovskite solar cells

“…This behavior can be attributed to the degradation of the Ag electrode caused by its reaction with iodine, which migrated from the perovskite layer. [101][102][103] The device incorporating SnS 2 nanosheets showed the worst stability, while the one containing MoSe 2 nanosheets exhibited similar behavior to the reference cell. On the other hand, the incorporation of InSe led to the disappearance of the burn-in phase, enhancing the cell stability.…”

An efficient approach for controlling the crystallization, strain, and defects of the perovskite film in hybrid perovskite solar cells through antisolvent engineering

“…The perovskite solution was prepared with the nominal stoichiometry Rb 0.05 Cs 0.04 (MA 0.15 FA 0.85 ) 0.91 Pb(I 0.90 Br 0.10 ) 3 as in our previous studies. 47,48 The perovskite layers were dynamically spin-coated onto the PTAA substrates at 6000 rpm for 45 s. At 20 s before the end of the spinning process, 200 mL of an anhydrous chlorobenzene (CB): isopropanol (IPA) (9 : 1 v/v) (99.8%, Sigma Aldrich, 99.8%, Acros Organics) mixture was dropped onto the spinning perovskite lm. For OABr (TCI) treated samples, solutions with different concentrations of OABr (0.01-0.25 mg mL −1 ) in CB/IPA (9 : 1 v/v) were prepared and used as antisolvent.…”