NiO_x/Spiro Hole Transport Bilayers for Stable Perovskite Solar Cells with Efficiency Exceeding 21%

Abstract

Hole transport layers (HTLs) play a crucial role in the efficiency and stability of perovskite solar cells (PSCs). The most efficient PSCs based on spiro-OMeTAD (Spiro) generally have stability problems. Here, NiO x /Spiro HTL has been designed and implemented by combining the advantages of these two films. The results indicated that a device based on a NiO x /Spiro HTL has faster hole extraction ability and better energy alignment than that of a pure Spiro device, thus improving the PCE from 19.8 to 21.66%. Compared with the 60% initial efficiency of Spiro-based devices, the NiO x /Spiro bilayer devices have higher stability and maintain 90% initial efficiency over 1200 h. In this work, NiO x is applied to perovskite devices with N−I−P configuration, which provides a possible mitigation strategy to reduce the V OC deficit for efficient and stable devices.

Understanding the Degradation of Spiro‐OMeTAD‐Based Perovskite Solar Cells at High Temperature

“…[ 32 ] The synthesized NiO x nanoparticles were dissolved in a mixture of chlorobenzene and OA (1:0.01 by volume). [ 54 ] The NiO x thin layer was deposited by spin coating from this solution at 1000 rpm for 30 s. The spin‐coated PMMA and NiO x thin layers were annealed at 100 °C for 10 min.…”

Ligand‐Modulated Excess PbI2 Nanosheets for Highly Efficient and Stable Perovskite Solar Cells

“…[ 41 ] Furthermore, the dark current density–voltage ( J –V) curve in Figure S14 (Supporting Information) showed the lower current density of CTAB‐modulated device in comparison with that of control device, indicating the suppressed charge‐carrier recombination and increased charge collection. [ 19,42–44 ]…”

Mechanisms and Suppression of Photoinduced Degradation in Perovskite Solar Cells

“…found that oleic acid can promote NiO x nanoparticles to be dispersed in chlorobenzene. [ 271 ] This helps them make n‐i‐p planar PSCs based on NiO x HTL, and the champion efficiency of the solar cells reaches 21.66%.…”

“…19.0 >350 h FTO/SnO 2 /C 60 -SAM/Perovskite/poly-VNPB/DMD AM 1.5 G, 50 °C, RH10% Poly-VNPB [286] (increased charge extraction and reduced recombination by Poly-VNPB) 2017 19.8 >300h glass/FTO/TiO 2 /perovskite/Z26/Au AM 1.5 G, N 2 Z26 [259] (high hole mobility) 2018 20.8 >300 h FTO/c-TiO 2 /mp-TiO 2 /(FAPbI 3 ) 0.95 (MAPbBr 3 ) 0.05 /DM/Au AM 1.5 G, 25 o C DM [287] (fine-tuned HOMO level and high glass transition temperature of DM) 2020 13.1 >100 h co-GR/MoS 2 /MAPbI 3 /PCBM/BCP/Al AM 1.5 G, 60 o C, RH 40% MoS 2 [288] (improved perovskite/HTL interface stability by MoS 2 ) 2019 18.5 >100 h FTO/mp-TiO2/PSK/P3HT(Li + TBP + Co)/Au AM 1.5 G P3HT(Li + TBP + Co) [36] (improved hole extraction by Co) 2019 18.5 ≈90 h ITO/NiO x /1ab/MAPbI 3 /PC 61 MB/BCP/Ag AM 1.5 G NiO x /1ab [289] (defect passivation by 1ab) nanoparticles to be dispersed in chlorobenzene. [271] This helps them make n-i-p planar PSCs based on NiO x HTL, and the champion efficiency of the solar cells reaches 21.66%.…”