High‐Mobility Hydrophobic Conjugated Polymer as Effective Interlayer for Air‐Stable Efficient Perovskite Solar Cells

Abstract

Hybrid organic–inorganic perovskite (HOIP) solar cells have achieved a certified power conversion efficiency (PCE) of 22.7%, which commonly use doped spiro‐OMeTAD as hole transport materials (HTMs). However, the additives in spiro‐OMeTAD can absorb moisture and cause the degradation of HOIP layers, leading to severe air‐instability of devices. Herein, conjugated polymers of PD‐10‐DTTE‐7 as a new effective interlayer between perovskite and doped spiro‐OMeTAD to achieve air‐stable efficient perovskite solar cells are reported. Its hydrophobic nature can effectively prevent the penetration of moisture and additives. Its superb hole mobility (9.54 cm2 V−1 s−1, ≈105 times higher than spiro‐OMeTAD) and suitable highest occupied molecular orbital level (−5.33 eV) are preferable to the hole injection and transport at the interface thus enhancing the device PCE. As a result, the MAPbI3 solar cells with the PD‐10‐DTTE‐7 interlayer achieve remarkable device air‐stability and enhanced PCE, compared with the devices without the interlayer. These results provide a feasible approach to enhance solar cell stability and performance simultaneously.

Surfactant Sodium Dodecyl Benzene Sulfonate Improves the Efficiency and Stability of Air‐Processed Perovskite Solar Cells with Negligible Hysteresis

“…Theoretically, R ct reflects the carrier transport dynamics at the interface, such as perovskite/SnO 2 and perovskite/Spiro‐OMeTAD interfaces. [ 72 ] Therefore, it suggested a more efficient charge extraction/transport and weaker carrier recombination in MAPbI 3 –SDBS‐based PSCs, which can be attributed to the introduction of SDBS additive resulting in a smoother surface and fewer defects, further improving the interface contact between perovskite and Spiro‐OMeTAD layer.…”

“…[ 34–38 ] Introduction of a thin buffer interlayer between the perovskite layer and the HTL is another promising way to prevent moisture ingress. [ 39,40 ] A limitation of this method is high‐cost and complex fabrication processes, which hamper the future practical applications of PSCs. Thus, it remains a challenge to develop facile and effective protocols to improve device's long‐term stability.…”

Stable and High‐Efficiency Methylammonium‐Free Perovskite Solar Cells

“…Hybrid organic–inorganic metal halide perovskite solar cells (PSCs) have attracted much attention owing to the rapid development of their PCE from 3.8% to above 25% in the past few years . Due to favorable optical bandgap and thermal stability, formamidinium (FA) was used as the cation in most of high efficiency PSCs .…”

Fabrication and characterization of lead‐free Cs 2 SnI 6 perovskite films for photovoltaic applications

“…Recently, the organic‐inorganic perovskite materials have sparked enormous attention at the forefront of the emerging photovoltaic technologies thanks to their extraordinary virtues involving light harvesting ability, easy fabrication methods, optimal bandgaps, and long carrier diffusion length 1‐5 . Intensive research and development of perovskite solar cells have resulted in a rapid increase in Power conversion from 3.5% to 25.2%, which is on par with the silicon solar cells 6‐11 . Among the organic‐inorganic perovskites, lead‐based perovskites (APbX 3 , A = Cs+, FA + or MA + , X = I, Br, or mixture) have been extensively explored due to their suitable bandgap and attractive optoelectronic properties 3,4,12 .…”