nz1c00794_si_001.pdf (1.62 MB)
Download fileInterfacial Defect Passivation and Stress Release via Multi-Active-Site Ligand Anchoring Enables Efficient and Stable Methylammonium-Free Perovskite Solar Cells
journal contribution
posted on 2021-06-18, 15:05 authored by Baibai Liu, Huan Bi, Dongmei He, Le Bai, Wenqi Wang, Hongkuan Yuan, Qunliang Song, Pengyu Su, Zhigang Zang, Tingwei Zhou, Jiangzhao ChenInterfacial
trap-assisted non-radiative recombination and residual
stress impede the further increase of power conversion efficiency
(PCE) and stability of the methylammonium-free (MA-free) perovskite
solar cells (PSCs). Here, we report an interfacial defect passivation
and stress release strategy through employing the multi-active-site
Lewis base ligand (i.e., (5-mercapto-1,3,4-thiadiazol-2-ylthio)acetic
acid (MTDAA)) to modify the surface and grain boundaries (GBs) of
MA-free perovskite films. Both experimental and theoretical results
confirm strong chemical interactions between multiple active sites
in the MTDAA molecule and undercoordinated Pb2+ at the
surface or GBs of perovskite films. It is demonstrated theoretically
that multi-active-site adsorption is more favorable thermodynamically
as compared to single-active-site adsorption, regardless of PbI2 termination and formamidinium iodide (FAI) termination types.
MTDAA modification results in much reduced defect density, increased
carrier lifetime, and almost thoroughly released interfacial residual
stress. Upon MTDAA passivation, the PCE is boosted from 20.26% to
21.92%. The unencapsulated device modified by MTDAA maintains 99%
of its initial PCE after aging under the relative humidity range of
10–20% for 1776 h, and 91% after aging at 60 °C for 1032
h.
History
Usage metrics
Read the peer-reviewed publication
Categories
Keywords
Multi-Active-Site Ligand Anchoring ...GBPbI 2 terminationpower conversion efficiencyPCEdefect densitymulti-active-site Lewis base ligandperovskite filmsMTDAA passivation1032 hPSCMTDAA moleculeMA-free perovskite films1776 hgrain boundariesMTDAA modification resultsunencapsulated devicechemical interactionsdefect passivationsingle-active-site adsorptionInterfacial Defect Passivationsurfacecarrier lifetimetermination typesstress release strategyFAIStress Releaseformamidinium iodidehumidity rangemulti-active-site adsorptionStable Methylammonium-Free Perovski...