Title: Unraveling the Impact of Halide Mixing on Perovskite Stability

Abstract

Increasing the stability of perovskites is essential for their integration in commercial photovoltaic devices. Halide mixing is suggested as a powerful strategy toward stable perovskite materials. However, the stabilizing effect of the halides critically depends on their distribution in the mixed compound, a topic that is currently under intense debate. In this paper, we successfully determine the exact location of the I and Cl anions in the CH₃NH₃PbBr_3–yI_y and CH₃NH₃PbBr_3–zCl_z mixed halide perovskite lattices and correlate it with the enhanced stability we find for the latter. By combining scanning tunneling microscopy and density functional theory, we predict that, for low ratios, iodine and chlorine incorporation have different effects on the electronic properties and stability of the CH₃NH₃PbBr₃ perovskite material. In addition, we determine the optimal Cl incorporation ratio for stability increase without detrimental band gap modification, providing an important direction for the fabrication of stable perovskite devices. The increased material stability induced by chlorine incorporation is verified by performing photoelectron spectroscopy on a half-cell device architecture. Our findings provide an answer to the current debate on halide incorporation and demonstrate their direct influence on device stability.

Authors:

Hieulle, Jeremy  ^[1];

• Search DOE PAGES for author "Hieulle, Jeremy"
• Search DOE PAGES for ORCID "0000-0003-4891-4007"

Wang, Xiaoming  ^[2];

• Search DOE PAGES for author "Wang, Xiaoming"
• Search DOE PAGES for ORCID "0000-0002-5438-1334"

Stecker, Collin ^[1]; Son, Dae-Yong ^[1]; Qiu, Longbin ^[1]; Ohmann, Robin  ^[3];

• Search DOE PAGES for author "Ohmann, Robin"
• Search DOE PAGES for ORCID "0000-0003-2483-1282"

Ono, Luis K. ^[1]; Mugarza, Aitor  ^[4];

• Search DOE PAGES for author "Mugarza, Aitor"
• Search DOE PAGES for ORCID "0000-0002-2698-885X"

Yan, Yanfa  ^[2];

• Search DOE PAGES for author "Yan, Yanfa"
• Search DOE PAGES for ORCID "0000-0003-3977-5789"

Qi, Yabing  ^[1]

• Search DOE PAGES for author "Qi, Yabing"
• Search DOE PAGES for ORCID "0000-0002-4876-8049"

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+ Show Author Affiliations

1. Okinawa Inst. of Science and Technology Graduate Univ. (OIST), Onna-son, Okinawa (Japan). Energy Materials and Surface Sciences Unit (EMSSU)
2. Univ. of Toledo, Toledo, OH (United States). Dept. of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization
3. Okinawa Inst. of Science and Technology Graduate Univ. (OIST), Onna-son, Okinawa (Japan). Energy Materials and Surface Sciences Unit (EMSSU); Univ. Siegen, Seigen (Germany). Dept. Physik
4. CSIC and The Barcelona Inst. of Science and Technology, Barcelona (Spain). Catalan Inst. of Nanoscience and Nanotechnology (ICN2); Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona (Spain)

Publication Date:

Tue Jan 15 00:00:00 EST 2019

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Center for Hybrid Organic-Inorganic Semiconductors for Energy (CHOISE); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1542287

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Journal of the American Chemical Society

Additional Journal Information:

Journal Volume: 141; Journal Issue: 8; Journal ID: ISSN 0002-7863

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY