High‐Performance Perovskite Solar Cells with Excellent Humidity and Thermo‐Stability via Fluorinated Perylenediimide

Abstract

The notoriously poor stability of perovskite solar cells is a crucial issue restricting commercial applications. Here, a fluorinated perylenediimide (F‐PDI) is first introduced into perovskite film to enhance the device's photovoltaic performance, as well as thermal and moisture stability simultaneously. The conductive F‐PDI molecules filling at grain boundaries (GBs) and surface of perovskite film can passivate defects and promote charge transport through GBs due to the chelation between carbonyl of F‐PDI and noncoordinating lead. Furthermore, an effective multiple hydrophobic structure is formed to protect perovskite film from moisture erosion. As a result, the F‐PDI‐incorporated devices based on MAPbI3 and Cs0.05 (FA0.83MA0.17)0.95 Pb (Br0.17I0.83)3 absorber achieve champion efficiencies of 18.28% and 19.26%, respectively. Over 80% of the initial efficiency is maintained after exposure in air for 30 days with a relative humidity (RH) of 50%. In addition, the strong hydrogen bonding of F···H‐N can immobilize methylamine ion (MA+) and thus enhances the thermal stability of device, remaining nearly 70% of the initial value after thermal treatment (100 °C) for 24 h at 50% RH condition.

Secondary Ion Mass Spectrometry (SIMS) for Chemical Characterization of Metal Halide Perovskites

“…The incorporation of fluorinated perylenediimide (F-PDI) in MAPbI 3 and Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(Br 0.17 I 0.83 ) 3 leads to the devices maintaining 80% of the initial PCE after exposure to a relative humidity of 50% for 30 days. [97] In the reference device (no F-PDI), the I − diffused across the PCBM layer to the Ag electrode and the Ag diffused across the PCBM layer to the perovskite layer, as shown by the ToF-SIMS depth profiles in Figure 12c. However, the I − diffusion and the Ag diffusion is significantly suppressed in the F-PDI-containing device (Figure 12c), indicating that F-PDI suppresses ion diffusion in the perovskite solar cells.…”

“…c) ToF-SIMS depth profiles of Ag and I of the perovskite solar cells with and without the incorporation of F-PDI, both devices were aged in air at 85 °C for 10 h. Reproduced with permission. [97] Copyright 2019, Wiley-VCH. d,e) ToF-SIMS 3D tomography (measurement area 50*50 µm) of Cl distribution in FTO/Bl-TiO 2 /mp-TiO 2 / perovskite, (d) no MDACl 2 additive in perovskite layer, (e) with 3.8 mol% MDACl 2 as additive in perovskite layer.…”

“…However, the I − diffusion and the Ag diffusion is significantly suppressed in the F-PDI-containing device (Figure 12c), indicating that F-PDI suppresses ion diffusion in the perovskite solar cells. [97] Organic molecules as additives can also improve the performance of perovskite light-emitting diodes (LEDs). It was shown that the 1,3,5-tris(2-N-phenylbenzimidazolyl) benzene (TPBI) in perovskite can suppress trap assisted nonradiative recombination and reach electron-hole balance in perovskite LEDs.…”

Efficient Passivation with Lead Pyridine‐2‐Carboxylic for High‐Performance and Stable Perovskite Solar Cells

“…[21,22] At elevated temperature, the volatility of methylamine (MA) cations leads to the thermal decomposition of methylammoniun lead iodide (MAPbI 3 ) perovskite. [21,22] At elevated temperature, the volatility of methylamine (MA) cations leads to the thermal decomposition of methylammoniun lead iodide (MAPbI 3 ) perovskite.…”

Self‐Additive Low‐Dimensional Ruddlesden–Popper Perovskite by the Incorporation of Glycine Hydrochloride for High‐Performance and Stable Solar Cells

“…Perovskite light absorption materials have poor chemical stability and are easily degraded in environmental conditions, such as UV light, oxygen, humidity, and high temperature. [ 10–15 ] Many solutions have been proposed to improve the long‐term stability, such as interface engineering, [ 16,17 ] controlling the crystal structure, [ 18,19 ] encapsulation, [ 20,21 ] and designing the perovskite materials. [ 22,23 ] The preparation of low‐dimensional Ruddlesden–Popper (RP) perovskites has become one of the most promising measures.…”