Regulation of the luminescence mechanism of two-dimensional tin halide perovskites

AbstractTwo-dimensional (2D) Sn-based perovskites are a kind of non-toxic environment-friendly luminescent material. However, the research on the luminescence mechanism of this type of perovskite is still very controversial, which greatly limits the further improvement and application of the luminescence performance. At present, the focus of controversy is defects and phonon scattering rates. In this work, we combine the organic cation control engineering with temperature-dependent transient absorption spectroscopy to systematically study the interband exciton relaxation pathways in layered A2SnI4 (A = PEA+, BA+, HA+, and OA+) structures. It is revealed that exciton-phonon scattering and exciton-defect scattering have different effects on exciton relaxation. Our study further confirms that the deformation potential scattering by charged defects, not by the non-polar optical phonons, dominates the excitons interband relaxation, which is largely different from the Pb-based perovskites. These results enhance the understanding of the origin of the non-radiative pathway in Sn-based perovskite materials.

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Manipulation of hot carrier cooling dynamics in two-dimensional Dion–Jacobson hybrid perovskites via Rashba band splitting

Nature Communications ◽

10.1038/s41467-021-24258-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jun Yin ◽

Rounak Naphade ◽

Partha Maity ◽

Luis Gutiérrez-Arzaluz ◽

Dhaifallah Almalawi ◽

...

Keyword(s):

Transient Absorption ◽

Phonon Scattering ◽

Transient Absorption Spectroscopy ◽

Band Model ◽

Two Dimensional ◽

Spintronic Devices ◽

Hot Carrier ◽

Band Splitting ◽

Perovskite Materials ◽

Spin Polarized

AbstractHot-carrier cooling processes of perovskite materials are typically described by a single parabolic band model that includes the effects of carrier-phonon scattering, hot phonon bottleneck, and Auger heating. However, little is known (if anything) about the cooling processes in which the spin-degenerate parabolic band splits into two spin-polarized bands, i.e., the Rashba band splitting effect. Here, we investigated the hot-carrier cooling processes for two slightly different compositions of two-dimensional Dion–Jacobson hybrid perovskites, namely, (3AMP)PbI4 and (4AMP)PbI4 (3AMP = 3-(aminomethyl)piperidinium; 4AMP = 4-(aminomethyl)piperidinium), using a combination of ultrafast transient absorption spectroscopy and first-principles calculations. In (4AMP)PbI4, upon Rashba band splitting, the spin-dependent scattering of hot electrons is responsible for accelerating hot-carrier cooling at longer delays. Importantly, the hot-carrier cooling of (4AMP)PbI4 can be extended by manipulating the spin state of the hot carriers. Our findings suggest a new approach for prolonging hot-carrier cooling in hybrid perovskites, which is conducive to further improving the performance of hot-carrier-based optoelectronic and spintronic devices.

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Ultrafast Triplet Generation at the Lead Halide Perovskite/Rubrene Interface

10.26434/chemrxiv-2021-rp36t ◽

2021 ◽

Author(s):

Carl Conti ◽

Alexander Bieber ◽

Zachary VanOrman ◽

Gregory Moller ◽

Sarah Wieghold ◽

...

Keyword(s):

Transient Absorption ◽

Underlying Mechanism ◽

Transient Absorption Spectroscopy ◽

Trap States ◽

Photovoltaic Devices ◽

Data Points ◽

Halide Perovskites ◽

Absorption Features ◽

Lead Halide ◽

Visible Photon

Triplet sensitization of rubrene by bulk lead halide perovskites has recently resulted in efficient infrared-to-visible photon upconversion via triplet-triplet annihilation. Notably, this process occurrs under solar relavant fluxes, potentially paving the way toward integration with photovoltaic devices. In order to further improve the upconversion efficiency, the fundamental photophysical pathways at the perovskite/rubrene interface must be clearly understood to maximize charge extraction. Here, we utilize ultrafast transient absorption spectroscopy to elucidate the processes underlying the triplet generation at the perovskite/rubrene interface. Based on the bleach and photoinduced absorption features of the perovskite and perovskite/rubrene devices obtained at multiple pump wavelengths and fluences, along with their resultant kinetics, our results do not support charge transfer states or long-lived trap states as the underlying mechanism. Instead, the data points towards a triplet sensitization mechanism based on rapid extraction of thermally excited carriers on the picosecond timescale.

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Widely tunable cavity-enhanced ultrafast spectroscopy

EPJ Web of Conferences ◽

10.1051/epjconf/201920501024 ◽

2019 ◽

Vol 205 ◽

pp. 01024

Author(s):

Myles C. Silfies ◽

Yuning Chen ◽

Henry Timmers ◽

Abijith S. Kowligy ◽

Alex Lind ◽

...

Keyword(s):

Gas Phase ◽

Absorption Spectroscopy ◽

Ultrafast Spectroscopy ◽

Transient Absorption ◽

Transient Absorption Spectroscopy ◽

Two Dimensional ◽

Frequency Combs ◽

Gas Phase Clusters ◽

Uv Visible ◽

Tunable Frequency

Generation of widely tunable frequency combs in the UV, visible, and infrared is discussed for use in cavity-enhanced transient absorption spectroscopy on gas-phase clusters. Progress towards cavity-enhanced two-dimensional spectroscopy is also presented.

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Temperature-Dependent Evolution of Raman Spectra of Methylammonium Lead Halide Perovskites, CH3NH3PbX3 (X = I, Br)

Molecules ◽

10.3390/molecules24030626 ◽

2019 ◽

Vol 24 (3) ◽

pp. 626 ◽

Cited By ~ 19

Author(s):

Kousuke Nakada ◽

Yuki Matsumoto ◽

Yukihiro Shimoi ◽

Koji Yamada ◽

Yukio Furukawa

Keyword(s):

Phase Transitions ◽

Temperature Dependence ◽

Temperature Dependent ◽

High Power Conversion Efficiency ◽

Perovskite Materials ◽

Hybrid Perovskite ◽

Temperature Ranges ◽

Raman Study ◽

Halide Perovskites ◽

Motional Narrowing

We present a Raman study on the phase transitions of organic/inorganic hybrid perovskite materials, CH3NH3PbX3 (X = I, Br), which are used as solar cells with high power conversion efficiency. The temperature dependence of the Raman bands of CH3NH3PbX3 (X = I, Br) was measured in the temperature ranges of 290 to 100 K for CH3NH3PbBr3 and 340 to 110 K for CH3NH3PbI3. Broad ν1 bands at ~326 cm−1 for MAPbBr3 and at ~240 cm−1 for MAPbI3 were assigned to the MA–PbX3 cage vibrations. These bands exhibited anomalous temperature dependence, which was attributable to motional narrowing originating from fast changes between the orientational states of CH3NH3+ in the cage. Phase transitions were characterized by changes in the bandwidths and peak positions of the MA–cage vibration and some bands associated with the NH3+ group.

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Exploring the Ruddlesden−Popper Layered Organic-Inorganic Hybrid Semiconducting Perovskite for Visible-Blind Ultraviolet Photodetection

CrystEngComm ◽

10.1039/d1ce01431e ◽

2021 ◽

Author(s):

Yuyin Wang ◽

Bin Su ◽

Guoming Lin ◽

Huiru Lou ◽

Shouxin Wang ◽

...

Keyword(s):

Physical Properties ◽

Three Dimensional ◽

Metal Halide ◽

Two Dimensional ◽

Inorganic Hybrid ◽

Perovskite Materials ◽

Halide Perovskites ◽

P Type ◽

Visible Blind

Compared to the three-dimensional (3D) perovskite materials, the Ruddlesden−Popper (R-P) type two-dimensional (2D) organic-inorganic metal halide perovskites have indicated specific unique physical properties that include moisture-stable behaviours, exciton effects, and...

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Bromine substitution improves excited-state dynamics in mesoporous mixed halide perovskite films

Nanoscale ◽

10.1039/c7nr04267a ◽

2017 ◽

Vol 9 (33) ◽

pp. 12005-12013 ◽

Cited By ~ 17

Author(s):

Eric M. Talbert ◽

Holly F. Zarick ◽

Abdelaziz Boulesbaa ◽

Naiya Soetan ◽

Alexander A. Puretzky ◽

...

Keyword(s):

Excited State ◽

Absorption Spectroscopy ◽

Transient Absorption ◽

Carrier Dynamics ◽

Transient Absorption Spectroscopy ◽

Excited State Dynamics ◽

Halide Perovskites ◽

Halide Perovskite ◽

Carrier Thermalization ◽

The Impact

This study investigates the impact of Br substitution on the carrier dynamics in mixed halide perovskites using ultrafast transient absorption spectroscopy, revealing faster carrier thermalization lifetimes with increasing Br content.

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Seeded growth of single-crystal two-dimensional covalent organic frameworks

Science ◽

10.1126/science.aar7883 ◽

2018 ◽

Vol 361 (6397) ◽

pp. 52-57 ◽

Cited By ~ 176

Author(s):

Austin M. Evans ◽

Lucas R. Parent ◽

Nathan C. Flanders ◽

Ryan P. Bisbey ◽

Edon Vitaku ◽

...

Keyword(s):

Transient Absorption ◽

Molecular Transport ◽

Transient Absorption Spectroscopy ◽

Two Dimensional ◽

Covalent Organic Frameworks ◽

Seeded Growth ◽

Step Procedure ◽

Structures And Properties ◽

Powder Samples ◽

2D Polymer

Polymerization of monomers into periodic two-dimensional networks provides structurally precise, layered macromolecular sheets that exhibit desirable mechanical, optoelectronic, and molecular transport properties. Two-dimensional covalent organic frameworks (2D COFs) offer broad monomer scope but are generally isolated as powders comprising aggregated nanometer-scale crystallites. We found that 2D COF formation could be controlled using a two-step procedure in which monomers are added slowly to preformed nanoparticle seeds. The resulting 2D COFs are isolated as single-crystalline, micrometer-sized particles. Transient absorption spectroscopy of the dispersed COF nanoparticles revealed improvement in signal quality by two to three orders of magnitude relative to polycrystalline powder samples, and suggests exciton diffusion over longer length scales than those obtained through previous approaches. These findings should enable a broad exploration of synthetic 2D polymer structures and properties.

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UV Two-Dimensional Transient Absorption Spectroscopy

Research in Optical Sciences ◽

10.1364/icusd.2012.im3d.1 ◽

2012 ◽

Author(s):

Gerald Auböck ◽

Cristina Consani ◽

Frank van Mourik ◽

Majed Chergui

Keyword(s):

Absorption Spectroscopy ◽

Transient Absorption ◽

Transient Absorption Spectroscopy ◽

Two Dimensional

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A Phonon Scattering Bottleneck for Carrier Cooling in Lead-Chalcogenide Nanocrystals

MRS Proceedings ◽

10.1557/opl.2015.595 ◽

2015 ◽

Vol 1787 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Pieter Geiregat ◽

Christophe Delerue ◽

Yolanda Justo ◽

Michiel Aerts ◽

Frank Spoor ◽

...

Keyword(s):

Critical Point ◽

Transient Absorption ◽

Phonon Scattering ◽

High Energy ◽

Charge Carriers ◽

Transient Absorption Spectroscopy ◽

Lead Chalcogenide ◽

Lead Chalcogenides ◽

Hot Carrier ◽

Slowing Down

ABSTRACTThe cooling dynamics of hot charge carriers in colloidal lead chalcogenide nanocrystals is studied by white light transient absorption spectroscopy. We demonstrate a transient accumulation of charge carriers at a high-energy critical point in the Brillouin zone. Using a theoretical study of the cooling rate in lead chalcogenides, we attribute this slowing down of charge carrier cooling to a phonon scattering bottleneck around this critical point. Our approach allows for the first ever determination of hot carrier cooling rates, relevant in e.g. modeling of multiple exciton generation.

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