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Title: Dynamic Evolution of 2D Layers within Perovskite Nanocrystals via Salt Pair Extraction and Reinsertion

Abstract

Metal halide perovskite (MHP) semiconductors exhibit unprecedented optoelectronic properties coupled with low formation energies that enable scalable, cost-efficient solution processing. The low formation energies additionally facilitate dynamic transformation of the chemical composition and crystal structure of the MHP material. In this work, we show that CsBr salt is selectively extracted from CsPbBr 3 nanocrystals (NCs) to yield PbBr 2 NCs. The PbBr 2 NCs are then exposed to different glacial acetic acid ABr salt solutions to generate a variety of emissive compounds with the generic structure A' 2A n-1Pb nBr 3 n-1X' 2, where A = cesium (Cs +), methylammonium (MA +), formamidinium (FA+); A' = A or H+; X' = Br- or acetate (CH3COO-); and n is the number of lead halide layers, where n = 1, 2, 3, ...8. We systematically vary the ratios of PbBr 2/ABr/CH 3COOH and show that certain ratios result in isolable single-phase APbBr3 NCs - an effective A-site cation exchange from the parent CsPbBr 3 NCs. Importantly, time-resolved photoluminescence (PL) spectroscopy shows the dynamic evolution of many additional species as evidenced by blue-shifted emission peaks from 2.85-2.49 eV for MA +-based structures. We assign these species to n = 1, 2, 3, 4,more » and 5 quasi-two-dimensional network (2DN) sheets, in which CH 3COO- anions and Br- anions compete for the c-axis X' sites separating haloplumbate(II) layers within the A' 2A n-1Pb nBr 3n-1X' 2 NCs. Finally, we demonstrate the degree of CH 3COO- incorporation, and thus the 2DN layer thickness and PL energy, is controlled in the early reaction times by kinetic factors. After a longer time (3 h), thermodynamic forces dictated by Le Chatelier's principle tune the structure in A' 2A n-1Pb nBr 3n-1X' 2 NCs from exclusively n = 1 to n = 8 depending on the PbBr 2/ABr/CH 3COOH ratio.« less

Authors:
 [1];  [1];  [2]; ORCiD logo [3]; ORCiD logo [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Florida, Gainesville, FL (United States)
  3. National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Southern Illinois, Carbondale, IL (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1456865
Report Number(s):
NREL/JA-5900-70903
Journal ID: ISSN 1932-7447
Grant/Contract Number:  
AC36-08GO28308
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 122; Journal Issue: 25; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; layered perovskite; perovskite nanocrystal; two-dimensional semiconductors; two-dimensional network; cation exchange; quantum confinement

Citation Formats

Wheeler, Lance M., Anderson, Nicholas C., Bliss, Taylor S., Hautzinger, Matthew P., and Neale, Nathan R. Dynamic Evolution of 2D Layers within Perovskite Nanocrystals via Salt Pair Extraction and Reinsertion. United States: N. p., 2018. Web. doi:10.1021/acs.jpcc.8b01164.
Wheeler, Lance M., Anderson, Nicholas C., Bliss, Taylor S., Hautzinger, Matthew P., & Neale, Nathan R. Dynamic Evolution of 2D Layers within Perovskite Nanocrystals via Salt Pair Extraction and Reinsertion. United States. doi:10.1021/acs.jpcc.8b01164.
Wheeler, Lance M., Anderson, Nicholas C., Bliss, Taylor S., Hautzinger, Matthew P., and Neale, Nathan R. Sat . "Dynamic Evolution of 2D Layers within Perovskite Nanocrystals via Salt Pair Extraction and Reinsertion". United States. doi:10.1021/acs.jpcc.8b01164. https://www.osti.gov/servlets/purl/1456865.
@article{osti_1456865,
title = {Dynamic Evolution of 2D Layers within Perovskite Nanocrystals via Salt Pair Extraction and Reinsertion},
author = {Wheeler, Lance M. and Anderson, Nicholas C. and Bliss, Taylor S. and Hautzinger, Matthew P. and Neale, Nathan R.},
abstractNote = {Metal halide perovskite (MHP) semiconductors exhibit unprecedented optoelectronic properties coupled with low formation energies that enable scalable, cost-efficient solution processing. The low formation energies additionally facilitate dynamic transformation of the chemical composition and crystal structure of the MHP material. In this work, we show that CsBr salt is selectively extracted from CsPbBr3 nanocrystals (NCs) to yield PbBr2 NCs. The PbBr2 NCs are then exposed to different glacial acetic acid ABr salt solutions to generate a variety of emissive compounds with the generic structure A'2An-1PbnBr3n-1X'2, where A = cesium (Cs+), methylammonium (MA+), formamidinium (FA+); A' = A or H+; X' = Br- or acetate (CH3COO-); and n is the number of lead halide layers, where n = 1, 2, 3, ...8. We systematically vary the ratios of PbBr2/ABr/CH3COOH and show that certain ratios result in isolable single-phase APbBr3 NCs - an effective A-site cation exchange from the parent CsPbBr3 NCs. Importantly, time-resolved photoluminescence (PL) spectroscopy shows the dynamic evolution of many additional species as evidenced by blue-shifted emission peaks from 2.85-2.49 eV for MA+-based structures. We assign these species to n = 1, 2, 3, 4, and 5 quasi-two-dimensional network (2DN) sheets, in which CH3COO- anions and Br- anions compete for the c-axis X' sites separating haloplumbate(II) layers within the A'2An-1PbnBr3n-1X'2 NCs. Finally, we demonstrate the degree of CH3COO- incorporation, and thus the 2DN layer thickness and PL energy, is controlled in the early reaction times by kinetic factors. After a longer time (3 h), thermodynamic forces dictated by Le Chatelier's principle tune the structure in A'2An-1PbnBr3n-1X'2 NCs from exclusively n = 1 to n = 8 depending on the PbBr2/ABr/CH3COOH ratio.},
doi = {10.1021/acs.jpcc.8b01164},
journal = {Journal of Physical Chemistry. C},
issn = {1932-7447},
number = 25,
volume = 122,
place = {United States},
year = {2018},
month = {4}
}

Journal Article:
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Figures / Tables:

Scheme1. Scheme1.: Transformations of MHP NCs Based on CsBr Salt Extraction from CsPbBr3 NCs to Form PbBr2 NCs that Are Re-formed into A′2An−1PbnBr3n−1X′2 NCs via A′X′ Additiona

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Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.