Synthetic Variation and Structural Trends in Layered Two-Dimensional Alkylammonium Lead Halide Perovskites

Paritmongkol, Watcharaphol; Dahod, Nabeel S.; Stollmann, Alexia; Mao, Nannan; Settens, Charles; Zheng, Shao‐Liang; Tisdale, William A.

doi:10.1021/acs.chemmater.9b01318

Cited by 113 publications

(186 citation statements)

References 87 publications

(234 reference statements)

Supporting

Mentioning

158

Contrasting

Order By: Relevance

“…The hybridization determines the conduction band minimum (CBM) antibonding between p orbitals of metal and s/p hybrid orbitals of halide. Small octahedral tilting pushes up the VBM and pushes down the CBM, resulting in the reduced bandgap 21,22 .…”

Section: Resultsmentioning

confidence: 99%

Reduced-dimensional perovskite photovoltaics with homogeneous energy landscape

et al. 2020

View full text Add to dashboard Cite

Reduced-dimensional (quasi-2D) perovskite materials are widely applied for perovskite photovoltaics due to their remarkable environmental stability. However, their device performance still lags far behind traditional three dimensional perovskites, particularly high open circuit voltage (V oc) loss. Here, inhomogeneous energy landscape is pointed out to be the sole reason, which introduces extra energy loss, creates band tail states and inhibits minority carrier transport. We thus propose to form homogeneous energy landscape to overcome the problem. A synergistic approach is conceived, by taking advantage of material structure and crystallization kinetic engineering. Accordingly, with the help of density functional theory guided material design, (aminomethyl) piperidinium quasi-2D perovskites are selected. The lowest energy distribution and homogeneous energy landscape are achieved through carefully regulating their crystallization kinetics. We conclude that homogeneous energy landscape significantly reduces the Shockley-Read-Hall recombination and suppresses the quasi-Fermi level splitting, which is crucial to achieve high V oc .

show abstract

Section: Resultsmentioning

confidence: 99%

Reduced-dimensional perovskite photovoltaics with homogeneous energy landscape

et al. 2020

View full text Add to dashboard Cite

show abstract

“…[ 27 ] In this protocol, the relative amount of large cations was finely tuned to avoid the impurities of higher (e.g., n + 1) and/or lower (e.g., n − 1) RPPs. [ 28,29 ] Since the thermodynamic stability of the 2D phases is increased with decreasing n values, the amount of large organic cations used in the n = 2 and n = 3 syntheses was always kept below the stoichiometric molar ratio (Table S1, Supporting Information). It is worth noting that the hot solution (110 °C) was held for an hour after the solution turned to clear yellow under reflux.…”

Section: Resultsmentioning

confidence: 99%

Coordination Engineering of Single‐Crystal Precursor for Phase Control in Ruddlesden–Popper Perovskite Solar Cells

Qin

Zhong

Intemann

et al. 2020

Advanced Energy Materials

View full text Add to dashboard Cite

efficiencies (PCE). [1,2] However, the intrinsic instability of 3D perovskite materials still remains unresolved. [3,4] Inert bulky organic cations can not only enhance their structural stability via strong interactions between covering organic cations and the [PbI 6 ] − units, but also block moisture from penetrating and corroding inner inorganic layers. [5,6] By incorporation of a larger cation into the 3D structure, the most common type is the (100)-oriented cutting direction, forming representative Ruddlesden-Popper perovskite (RPP) with a chemical formula (A′) 2 (A) n−1 Pb n I 3n+1 (A′ is a primary monovalent cations). [7,8] Unfortunately, the confinement effects of organic spacers also lead to a strong quantum and dielectric confinement in 2D perovskite. Moreover, the decreased conductivity of the organic layers prevents the carrier charge transport between perovskite quantum wells. [9] Thus, RPP exhibits a wider bandgap, a higher exciton binding energy (E b ), and lower charge mobility relative to the 3D perovskites, which results in poor efficiencies. Note that a weak quantum confinement would arise from an increase thickness of layers (n value), leading to a remarkable decrease in the optical bandgap, making it highly desirable to increase the number (n ≥ 4) of inorganic sheets between two adjacent organic spacers by forming quasi-2D structures. [10,11] In addition, through rational design 2D Ruddlesden-Popper perovskites (RPPs) have recently drawn significant attention because of their structural variability that can be used to tailor optoelectronic properties and improve the stability of derived photovoltaic devices. However, charge separation and transport in 2D perovskite solar cells (PSCs) suffer from quantum well barriers formed during the processing of perovskites. It is extremely difficult to manage phase distributions in 2D perovskites made from the stoichiometric mixtures of precursor solutions. Herein, a generally applicable guideline is demonstrated for precisely controlling phase purity and arrangement in RPP films. By visually presenting the critical colloidal formation of the single-crystal precursor solution, coordination engineering is conducted with a rationally selected cosolvent to tune the colloidal properties. In nonpolar cosolvent media, the derived colloidal template enables RPP crystals to preferentially grow along the vertically ordered alignment with a narrow phase variation around a target value, resulting in efficient charge transport and extraction. As a result, a recordhigh power conversion efficiency (PCE) of 14.68% is demonstrated for a (TEA) 2 (MA) 2 Pb 3 I 10 (n = 3) photovoltaic device with negligible hysteresis. Remarkably, superior stability is achieved with 93% retainment of the initial efficiency after 500 h of unencapsulated operation in ambient air conditions.

show abstract

“…in which λ varies continuously from 0 to 1 and characterizes the strength of the electric field (we will set λ to unity at the end of the derivation). We desire a solution in the form of a power series expansion in λ:x = λx (1)…”

Section: A Solution To a Nonlinear Lorentz Modelmentioning

confidence: 99%

“…A key insight of perturbation theory is that for Equation S24 to be a valid solution of Equation S21 for any value of λ, the different terms in Equation S21 that are proportional to different powers of λ all must satisfy Equation S21 separately. We substitute Equation S23 and Equation S24 into Equation S21 and gather together, by powers of λ, terms up to λ 3 :ẍ (1) + 2γẋ (1) + ω 2 0x…”

Section: A Solution To a Nonlinear Lorentz Modelmentioning

confidence: 99%

See 1 more Smart Citation

Disentangling Second Harmonic Generation from Multiphoton Photoluminescence in Halide Perovskites using Multidimensional Harmonic Generation

Morrow

Hautzinger²,

Lafayette³

et al. 2020

Preprint

View full text Add to dashboard Cite

Metal halide perovskites are an intriguing class of semiconductor materials being explored for their linear and non-linear optical, and potentially ferroelectric properties. In particular, layered two-dimensional Ruddlesden-Popper (RP) halide perovskites have shown non-linear optoelectronic properties. Optical second harmonic generation (SHG) is commonly used to screen for non-centrosymmetric and ferroelectric materials, however, SHG measurements of perovskites are complicated by their intense multiphoton photoluminescence (mPL) which can be mistaken for SHG signal. In this work, we introduce multidimensional harmonic generation as a method to eliminate the complications caused by mPL. By scanning and correlating both excitation and emission frequencies, we un-ambiguously assess whether a material supports SHG by examining if an emission feature scales as twice the excitation frequency. Careful multidimensional harmonic generation measurements of a series of n=2 and n=3 RP perovskites reveal that, contrary to previous belief, n-butylammonium (BA) RP perovskites display no SHG, thus they have inversion symmetry; but RP perovskites with phenylethylammonium (PEA) and 2-thiophenemethylammonium (TPMA) spacer cations display SHG. Multidimensional harmonic generation is also able to confirm the SHG and thus non-centrosymmetry of a recently reported ferroelectric RP perovskite even in the presence of an obscuring mPL background. This work establishes multidimensional harmonic generation as a definitive method to measure the SHG properties of materials and demonstrates that tuning organic cations can allow the design of new non-centrosymmetric or even ferroelectric RP perovskites.<br>

show abstract

Synthetic Variation and Structural Trends in Layered Two-Dimensional Alkylammonium Lead Halide Perovskites

Cited by 113 publications

References 87 publications

Reduced-dimensional perovskite photovoltaics with homogeneous energy landscape

Reduced-dimensional perovskite photovoltaics with homogeneous energy landscape

Coordination Engineering of Single‐Crystal Precursor for Phase Control in Ruddlesden–Popper Perovskite Solar Cells

Disentangling Second Harmonic Generation from Multiphoton Photoluminescence in Halide Perovskites using Multidimensional Harmonic Generation

Contact Info

Product

Resources

About