Title: Combined Precursor Engineering and Grain Anchoring Leading to MA-Free, Phase-Pure, and Stable α-Formamidinium Lead Iodide Perovskites for Efficient Solar Cells

Abstract

Abstract α‐Formamidinium lead iodide (α‐FAPbI ₃ ) is one of the most promising candidate materials for high‐efficiency and thermally stable perovskite solar cells (PSCs) owing to its outstanding optoelectrical properties and high thermal stability. However, achieving a stable form of α‐FAPbI ₃ where both the composition and the phase are pure is very challenging. Herein, we report on a combined strategy of precursor engineering and grain anchoring to successfully prepare methylammonium (MA)‐free and phase‐pure stable α‐FAPbI ₃ films. The incorporation of volatile FA‐based additives in the precursor solutions completely suppresses the formation of non‐perovskite δ‐FAPbI ₃ during film crystallization. Grains of the desired α‐phase are anchored together and stabilized when 4‐ tert ‐butylbenzylammonium iodide is permeated into the α‐FAPbI ₃ film interior via grain boundaries. This cooperative scheme leads to a significantly increased efficiency close to 21 % for FAPbI ₃ perovskite solar cells. Moreover, the stabilized PSCs exhibit improved thermal stability and maintained ≈90 % of their initial efficiency after storage at 50 °C for over 1600 hours.

Authors:

Ling, Xufeng  ^[1];

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Zhu, Hongwei ^[2]; Xu, Weidong ^[3]; Liu, Cheng ^[4]; Pan, Linfeng ^[2]; Ren, Dan ^[2]; Yuan, Jianyu ^[4]; Larson, Bryon W. ^[5]; Gratzel, Carole ^[2]; Kirmani, Ahmad R. ^[5]; Ouellette, Olivier ^[2]; Krishna, Anurag ^[2]; Sun, Jianguo ^[4]; Zhang, Chunyang ^[2]; Li, Youyong ^[4]; Zakeeruddin, Shaik M. ^[2]; Gao, Jing ^[2]; Liu, Yuhang  ^[2];

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Durrant, James R. ^[6]; Luther, Joseph M.  ^[5]

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more »; Ma, Wanli ^[4]; Gratzel, Michael ^[2] « less

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+ Show Author Affiliations

1. Soochow University, Suzhou (China); Ecole Polytechnique Federale Lausanne (Switzerland)
2. Ecole Polytechnique Federale Lausanne (Switzerland)
3. Imperial College, London (United Kingdom)
4. Soochow University, Suzhou (China)
5. National Renewable Energy Lab. (NREL), Golden, CO (United States)
6. Imperial College, London (United Kingdom); Swansea Univ. (United Kingdom)

Publication Date:

2021-10-29

Research Org.:

National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE); National Key Research and Development (R&D) Program of China; National Natural Science Foundation of China (NSFC); Science and Technology Program of Jiangsu Province; Natural Science Foundation of Jiangsu Province; Postgraduate Research & Practice Innovation Program of Jiangsu Province; Natural Sciences and Engineering Research Council of Canada (NSERC)

OSTI Identifier:

1837995

Alternate Identifier(s):

OSTI ID: 1832055

Report Number(s):

NREL/JA-5900-80976
Journal ID: ISSN 1433-7851; MainId:79752;UUID:415ae31a-0df5-4f7a-a97f-6c35d70644dd;MainAdminID:63523

Grant/Contract Number:  

AC36-08GO28308; 2019YFE0108600; 2016YFA0202402; 52073198; 61911530158; 22161142003; BZ2020011; BK20211598; KYCX20_2645; EP/P032591/1

Resource Type:

Accepted Manuscript

Journal Name:

Angewandte Chemie (International Edition)

Additional Journal Information:

Journal Name: Angewandte Chemie (International Edition); Journal Volume: 60; Journal Issue: 52; Journal ID: ISSN 1433-7851

Publisher:

Wiley

Country of Publication:

United States

Language:

English

Subject:

14 SOLAR ENERGY; perovskite solar cells; α-FAPbI3; additive; stabilization; MA-free