Skip to content
DraconiticResearch
Search Sources API
203,203 studies31 sourcesUpdated 37 min ago
PreprintCC BY-NC-NDChemRxiv

Coordination Alone Does Not Passivate Surface Halide-Vacancy States in Lead Halide Perovskites

  • Christopher Gaspar Msigwa
  • Muhammad Mateen
  • Shibing Chu
Open at sourcePDFDOICite

Abstract

Molecular passivation of halide vacancies at lead-halide perovskite surfaces is conventionally attributed to Lewis-base coordination of undercoordinated Pb2+ sites. Density functional theory with spin–orbit coupling on FA0.75MA0.25PbI3 (001) shows this premise is electronically insufficient. Across ten additives, no coordination metric predicts which additives passivate: molybdic acid coordinates at 2.346 Å (−1.14 e) yet leaves the localized Pb(6p) defect trap intact (p = 0.128; +0.29 eV in HSE06), whereas permanganic acid coordinates at 2.156 Å (−1.06 e) and clears it (p ≤ 0.002). The outcomes exhibit discrete bimodal separation (Ashman’s D = 23.11) governed by specific interfacial chemistry: proton transfer forming a hydridic Pb–H bond (H2SO4, p = 0.008) or charge-transfer depopulation into an accessible acceptor manifold (HMnO4). This mechanism rationalizes the observed processing sensitivity of phosphate additives. Screening additives by coordination geometry cannot identify passivants; targeting proton delivery or redox-accessible acceptor levels can.

Related

  1. Energy-level alignment of vacancy-ordered halide double perovskites
    Ibrahim Buba Garba, George Volonakis
    Applied Physics LettersPeer-reviewedLicence not statedFull textGeneral chemistryHAL
  2. Role of local disorder in surface properties of inorganic halide perovskites
    Jasurbek Gulomov, Guido Roma, Marios Zacharias +2
    Physical Review MaterialsPeer-reviewedCC BY 4.0Full textMaterials & polymersTheoretical & computational chemistryHAL
  3. Chirality as a Structural Degree of Freedom in Halide Perovskites
    Suhas K. T., Ranjani Viswanatha
    ACS OmegaPeer-reviewedCC BY-NC-ND 4.0Full textGeneral chemistryCrossref
  4. The Intrinsic Photochemical (in)-Stability of Lead Halide Perovskites
    Emily de Bock, Claudia Pierdomenico, Alice E. M. Riot Rocquefelte +1
    ChemRxivPreprintCC BYGeneral chemistryChemRxiv
  5. Disentangling Electronic and Lattice Contributions to Transient Absorption in Metal Halide Perovskites: A First-Principles Study of CH3NH3PbBr3.
    Lu Qiao, Ronaldo Rodrigues Pela, Claudia Draxl
    Journal of the American Chemical SocietyPeer-reviewedCC BYFull textOrganic chemistryEurope PMC

Cite

BibTeXRIS
BibTeX
@misc{msigwa2026coordination,
  title = {{Coordination Alone Does Not Passivate Surface Halide-Vacancy States in Lead Halide Perovskites}},
  author = {Christopher Gaspar Msigwa and Muhammad Mateen and Shibing Chu},
  howpublished = {ChemRxiv},
  year = {2026},
  month = sep,
  doi = {10.26434/chemrxiv.15008619/v1},
  url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008619/v1},
  note = {CC BY-NC-ND},
}
RIS
TY  - UNPB
TI  - Coordination Alone Does Not Passivate Surface Halide-Vacancy States in Lead Halide Perovskites
AU  - Christopher Gaspar Msigwa
AU  - Muhammad Mateen
AU  - Shibing Chu
PY  - 2026
DA  - 2026/09/10
PB  - ChemRxiv
DO  - 10.26434/chemrxiv.15008619/v1
UR  - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008619/v1
AB  - Molecular passivation of halide vacancies at lead-halide perovskite surfaces is conventionally attributed to Lewis-base coordination of undercoordinated Pb2+ sites. Density functional theory with spin–orbit coupling on FA0.75MA0.25PbI3 (001) shows this premise is electronically insufficient. Across ten additives, no coordination metric predicts which additives passivate: molybdic acid coordinates at 2.346 Å (−1.14 e) yet leaves the localized Pb(6p) defect trap intact (p = 0.128; +0.29 eV in HSE06), whereas permanganic acid coordinates at 2.156 Å (−1.06 e) and clears it (p ≤ 0.002). The outcomes exhibit discrete bimodal separation (Ashman’s D = 23.11) governed by specific interfacial chemistry: proton transfer forming a hydridic Pb–H bond (H2SO4, p = 0.008) or charge-transfer depopulation into an accessible acceptor manifold (HMnO4). This mechanism rationalizes the observed processing sensitivity of phosphate additives. Screening additives by coordination geometry cannot identify passivants; targeting proton delivery or redox-accessible acceptor levels can.
ER  -