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Strain-Induced Metallization and Defect Suppression at Zipper-like Interdigitated Atomically Thin Interfaces Enabling High-Efficiency Halide Perovskite Solar Cells

Tsvetkov, Nikolai and Khan, Muhammad Ejaz and Moon, Byeong Cheul and Kim, Yong-Hoon and Kang, Jeung Ku (2021) Strain-Induced Metallization and Defect Suppression at Zipper-like Interdigitated Atomically Thin Interfaces Enabling High-Efficiency Halide Perovskite Solar Cells. ACS Nano, 15 (1). pp. 1805-1816. ISSN 1936-0851. https://resolver.caltech.edu/CaltechAUTHORS:20201217-133745225

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Abstract

Halide perovskite light absorbers have great advantages for photovoltaics such as efficient solar energy absorption, but charge accumulation and recombination at the interface with an electron transport layer (ETL) remain major challenges in realizing the absorbers’ full potential. Here we report the experimental realization of a zipper-like interdigitated interface between a Pb-based halide perovskite light absorber and an oxide ETL by the PbO capping of the ETL surface, which produces an atomically thin two-dimensional metallic layer that can significantly enhance the perovskite/ETL charge extraction process. As the atomistic origin of the emergent two-dimensional interfacial metallicity, first-principles calculations performed on the representative MAPbI₃/TiO₂ interface identify the interfacial strain induced by the simultaneous formation of stretched I-substitutional Pb bonds (and thus Pb–I–Pb bonds bridging MAPbI₃ and TiO₂) and contracted substitutional Pb–O bonds. Direct and indirect experimental evidence for the presence of interfacial metallic states are provided, and a nonconventional defect-passivating nature of the strained interdigitated perovskite/ETL interface is emphasized. It is experimentally demonstrated that the PbO capping method is generally applicable to other ETL materials, including ZnO and SrTiO₃, and that the zipper-like interdigitated metallic interface leads to about a 2-fold increase in the charge extraction rate. Finally, in terms of the photovoltaic efficiency, we observe a volcano-type behavior with the highest performance achieved at the monolayer-level PbO capping. This work establishes a general perovskite/ETL interface engineering approach to realize high-performance perovskite solar cells.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1021/acsnano.0c09584DOIArticle
ORCID:
AuthorORCID
Tsvetkov, Nikolai0000-0002-0074-1517
Khan, Muhammad Ejaz0000-0001-5415-5962
Moon, Byeong Cheul0000-0002-2927-9426
Kim, Yong-Hoon0000-0001-5209-4908
Kang, Jeung Ku0000-0003-3409-7544
Additional Information:© 2020 American Chemical Society. Received: November 14, 2020; Accepted: December 9, 2020; Published: December 15, 2020. This research was supported mainly by the Global Frontier R&D Center for Hybrid Interface Materials (Grant 2013M3A6B1078884) and the National Research Foundation of Korea (Grants 2017R1A2B3009872, 202019M3E6A1104196, 2020R1A4A2002806, and 2020H1D3A2A02104083). Computing resources were provided by the KISTI Supercomputing Center (Grant KSC-2018-CHA-0032). Author Contributions. N.T. and M.E.K. contributed equally to this work. The authors declare no competing financial interest.
Funders:
Funding AgencyGrant Number
Ministry of Science, ICT and Future Planning (Korea)2013M3A6B1078884
National Research Foundation of Korea2017R1A2B3009872
National Research Foundation of Korea202019M3E6A1104196
National Research Foundation of Korea2020R1A4A2002806
National Research Foundation of Korea2020H1D3A2A02104083
KISTI Supercomputing CenterKSC-2018-CHA-0032
Subject Keywords:strain-induced metallic states, zipper-like interdigitated atomically thin interfaces, efficient charge extraction, high efficiency, halide perovskite solar cells
Issue or Number:1
Record Number:CaltechAUTHORS:20201217-133745225
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20201217-133745225
Official Citation:Strain-Induced Metallization and Defect Suppression at Zipper-like Interdigitated Atomically Thin Interfaces Enabling High-Efficiency Halide Perovskite Solar Cells. Nikolai Tsvetkov, Muhammad Ejaz Khan, Byeong Cheul Moon, Yong-Hoon Kim, and Jeung Ku Kang. ACS Nano 2021 15 (1), 1805-1816; DOI: 10.1021/acsnano.0c09584
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107166
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:17 Dec 2020 22:52
Last Modified:28 Jan 2021 22:10

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