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Imidazole additives in 2D halide perovskites : impacts of -CN versus -CH3 substituents reveal the mediation of crystal growth by phase buffering

Yu, Shuang ; Meng, Jie LU ; Pan, Qinying LU ; Zhao, Qian ; Pullerits, Tõnu LU ; Yang, Yingguo ; Zheng, Kaibo LU and Liang, Ziqi (2022) In Energy and Environmental Science 15(8). p.3321-3330
Abstract

The unique sandwich structure and favorable crystallization kinetics have endowed two-dimensional (2D) halide perovskites with excellent ambient stability and facile film formation compared to those of their three-dimensional counterparts. However, the heterogeneous crystallization of multiple n-value phases during solution-casting of 2D perovskite thin films results in random and disordered crystalline alignment in conjunction with numerous lattice defects, all of which ultimately impair the device performance. Herein we demonstrate that highly ordered lattice arrangements in 2D lead halide perovskites, exemplified as a paradigm phenylethylamine (PEA) spacer, can be achieved using the 4,5-dicyanoimidazole (DCI) additive without any... (More)

The unique sandwich structure and favorable crystallization kinetics have endowed two-dimensional (2D) halide perovskites with excellent ambient stability and facile film formation compared to those of their three-dimensional counterparts. However, the heterogeneous crystallization of multiple n-value phases during solution-casting of 2D perovskite thin films results in random and disordered crystalline alignment in conjunction with numerous lattice defects, all of which ultimately impair the device performance. Herein we demonstrate that highly ordered lattice arrangements in 2D lead halide perovskites, exemplified as a paradigm phenylethylamine (PEA) spacer, can be achieved using the 4,5-dicyanoimidazole (DCI) additive without any post-treatment. Electrostatic potential distribution mapping and X-ray photoelectron spectroscopy collectively confirm the Lewis acid-base interaction between -CN− units in DCI and Pb2+, which is conducive to homogeneous nucleation during perovskite crystallization. A sequence of in situ grazing-incident wide-angle X-ray scattering and high-resolution transmission electron microscopy characterization unravel the epitaxial growth of multi-phases that gradually buffer the internal lattice strain and consequently regulate the lattice orientation, which markedly leads to a reduction of trap density and a prolongation of carrier lifetime. The resulting planar solar cells based on 2D PEA2MA3Pb4I13 (n = 4) deliver an outstanding efficiency of ∼17.0% along with excellent operational stability.

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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Energy and Environmental Science
volume
15
issue
8
pages
10 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:85132912918
ISSN
1754-5692
DOI
10.1039/d2ee00571a
language
English
LU publication?
yes
id
7c8d2a76-42f2-465b-9d0f-9d54adb0c04f
date added to LUP
2022-09-23 14:25:34
date last changed
2023-11-18 08:37:12
@article{7c8d2a76-42f2-465b-9d0f-9d54adb0c04f,
  abstract     = {{<p>The unique sandwich structure and favorable crystallization kinetics have endowed two-dimensional (2D) halide perovskites with excellent ambient stability and facile film formation compared to those of their three-dimensional counterparts. However, the heterogeneous crystallization of multiple n-value phases during solution-casting of 2D perovskite thin films results in random and disordered crystalline alignment in conjunction with numerous lattice defects, all of which ultimately impair the device performance. Herein we demonstrate that highly ordered lattice arrangements in 2D lead halide perovskites, exemplified as a paradigm phenylethylamine (PEA) spacer, can be achieved using the 4,5-dicyanoimidazole (DCI) additive without any post-treatment. Electrostatic potential distribution mapping and X-ray photoelectron spectroscopy collectively confirm the Lewis acid-base interaction between -CN<sup>−</sup> units in DCI and Pb<sup>2+</sup>, which is conducive to homogeneous nucleation during perovskite crystallization. A sequence of in situ grazing-incident wide-angle X-ray scattering and high-resolution transmission electron microscopy characterization unravel the epitaxial growth of multi-phases that gradually buffer the internal lattice strain and consequently regulate the lattice orientation, which markedly leads to a reduction of trap density and a prolongation of carrier lifetime. The resulting planar solar cells based on 2D PEA<sub>2</sub>MA<sub>3</sub>Pb<sub>4</sub>I<sub>13</sub> (n = 4) deliver an outstanding efficiency of ∼17.0% along with excellent operational stability.</p>}},
  author       = {{Yu, Shuang and Meng, Jie and Pan, Qinying and Zhao, Qian and Pullerits, Tõnu and Yang, Yingguo and Zheng, Kaibo and Liang, Ziqi}},
  issn         = {{1754-5692}},
  language     = {{eng}},
  month        = {{06}},
  number       = {{8}},
  pages        = {{3321--3330}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Energy and Environmental Science}},
  title        = {{Imidazole additives in 2D halide perovskites : impacts of -CN versus -CH<sub>3</sub> substituents reveal the mediation of crystal growth by phase buffering}},
  url          = {{http://dx.doi.org/10.1039/d2ee00571a}},
  doi          = {{10.1039/d2ee00571a}},
  volume       = {{15}},
  year         = {{2022}},
}