Title: Humidity-Induced Photoluminescence Hysteresis in Variable Cs/Br Ratio Hybrid Perovskites

Abstract

Hybrid organic–inorganic perovskites containing Cs are a promising new material for light-absorbing and light-emitting optoelectronics. However, the impact of environmental conditions on their optical properties is not fully understood. In this paper, we elucidate and quantify the influence of distinct humidity levels on the charge carrier recombination in Cs_xFA_1–xPb(I_yBr_1–y)₃ perovskites. Using in situ environmental photoluminescence (PL), we temporally and spectrally resolve light emission within a loop of critical relative humidity (rH) levels. Our measurements show that exposure up to 35% rH increases the PL emission for all Cs (10–17%) and Br (17–38%) concentrations investigated here. Spectrally, samples with larger Br concentrations exhibit PL redshift at higher humidity levels, revealing water-driven halide segregation. The compositions considered present hysteresis in their PL intensity upon returning to a low-moisture environment due to partially reversible hydration of the perovskites. Our findings demonstrate that the Cs/Br ratio strongly influences both the spectral stability and extent of light emission hysteresis. Finally, we expect our method to become standard when testing the stability of emerging perovskites, including lead-free options, and to be combined with other parameters known for affecting material degradation, e.g., oxygen and temperature.

Authors:

Howard, John M.  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-3990-5478"

Tennyson, Elizabeth M.  ^[1];

• Search DOE PAGES for author "Tennyson, Elizabeth M."
• Search DOE PAGES for ORCID "0000-0003-0071-8445"

Barik, Sabyasachi ^[2]; Szostak, Rodrigo ^[3]; Waks, Edo ^[4]; Toney, Michael F.  ^[5];

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• Search DOE PAGES for ORCID "0000-0002-7513-1166"

Nogueira, Ana F.  ^[6];

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• Search DOE PAGES for ORCID "0000-0002-0838-7962"

Neves, Bernardo R. A.  ^[7];

• Search DOE PAGES for author "Neves, Bernardo R. A."
• Search DOE PAGES for ORCID "0000-0003-0464-4754"

Leite, Marina S.  ^[1]

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• Search DOE PAGES for ORCID "0000-0003-4888-8195"

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+ Show Author Affiliations

1. Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering. Inst. for Research in Electronics and Applied Physics
2. Univ. of Maryland, College Park, MD (United States). Inst. for Research in Electronics and Applied Physics. Dept. of Physics
3. Univ. of Campinas (Brazil). Inst. of Chemistry
4. Univ. of Maryland, College Park, MD (United States). Inst. for Research in Electronics and Applied Physics. Dept. of Electrical and Computer Engineering
5. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource
6. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource; Univ. of Campinas (Brazil). Inst. of Chemistry
7. Univ. of Maryland, College Park, MD (United States). Inst. for Research in Electronics and Applied Physics; Federal Univ. of Minas Gerais, Belo Horizonte (Brazil). Dept. of Physics

Publication Date:

Fri Jun 08 00:00:00 EDT 2018

Research Org.:

SLAC National Accelerator Lab., Menlo Park, CA (United States); Univ. of Maryland, College Park, MD (United States); Univ. of Campinas (Brazil)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF); São Paulo Research Foundation (FAPESP) (Brazil)

OSTI Identifier:

1469619

Grant/Contract Number:  

AC02-76SF00515; 16-10833; 2017/12582-5; 2015/50450-8

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Physical Chemistry Letters

Additional Journal Information:

Journal Volume: 9; Journal Issue: 12; Journal ID: ISSN 1948-7185

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY