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

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.

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

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Tianju Zhang ◽  
Chaocheng Zhou ◽  
Xuezhen Feng ◽  
Ningning Dong ◽  
Hong Chen ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Phonon Scattering ◽  
Potential Scattering ◽  
Transient Absorption Spectroscopy ◽  
Two Dimensional ◽  
Temperature Dependent ◽  
Control Engineering ◽  
Perovskite Materials ◽  
Halide Perovskites ◽  
Charged Defects

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.

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

2015 ◽  
Vol 1787 ◽  
pp. 1-5 ◽  
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.

scholarly journals Ab Initio Simulation of Attosecond Transient Absorption Spectroscopy in Two-Dimensional Materials

2018 ◽  
Vol 8 (10) ◽  
pp. 1777 ◽  
Author(s):  
Shunsuke Sato ◽  
Hannes Hübener ◽  
Umberto De Giovannini ◽  
Angel Rubio
Keyword(s):  
Absorption Spectroscopy ◽  
Density Functional ◽  
Transient Absorption ◽  
Hexagonal Boron Nitride ◽  
Laser Pulses ◽  
Transient Absorption Spectroscopy ◽  
Band Model ◽  
Two Dimensional ◽  
Energy Bands ◽  
Two Dimensional Materials

We extend the first-principles analysis of attosecond transient absorption spectroscopy to two-dimensional materials. As an example of two-dimensional materials, we apply the analysis to monolayer hexagonal boron nitride (h-BN) and compute its transient optical properties under intense few-cycle infrared laser pulses. Nonadiabatic features are observed in the computed transient absorption spectra. To elucidate the microscopic origin of these features, we analyze the electronic structure of h-BN with density functional theory and investigate the dynamics of specific energy bands with a simple two-band model. Finally, we find that laser-induced intraband transitions play a significant role in the transient absorption even for the two-dimensional material and that the nonadiabatic features are induced by the dynamical Franz–Keldysh effect with an anomalous band dispersion.

scholarly journals Widely tunable cavity-enhanced ultrafast spectroscopy

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.

Hot carrier dynamics in HfN and ZrN measured by transient absorption spectroscopy

2016 ◽  
Vol 150 ◽  
pp. 51-56 ◽  
Author(s):  
Hongze Xia ◽  
Xiaoming Wen ◽  
Yu Feng ◽  
Robert Patterson ◽  
Simon Chung ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Carrier Dynamics ◽  
Transient Absorption Spectroscopy ◽  
Hot Carrier

Crystal structure and related electrical properties of ( N,N' -diethyl-4,4'-bipyridylium) 2+ - (7,7,8,8-tetracyanoqumodimethane) 2-/4

1975 ◽  
Vol 343 (1635) ◽  
pp. 461-475 ◽  
Keyword(s):  
Crystal Structure ◽  
Phonon Scattering ◽  
Charge Carriers ◽  
Band Model ◽  
Two Dimensional ◽  
Monoclinic System ◽  
Lattice Constants ◽  
Temperature Dependences ◽  
Electrical Data ◽  
Model Approach

The crystal structure, conductivity and thermoelectric power are reported of N,N' -diethyl-4,4'-bipyridylium (TCNQ) 4 . The complex crystallizes in the monoclinic system with the space group P2 1 /c and lattice constants a = 13.077, b = 25.316, c = 7.838 Å, β = 92.66° and having Z = 2. The anisotropic electrical data are discussed in terms of the crystal structure. A band model approach to conduction is suggested with phonon scattering of charge carriers within a two dimensional TCNQ lattice. Temperature dependences of mobility of T -1.6 and T -1.1 for electron and hole respectively were obtained.

scholarly journals Bottleneck-Free Hot Hole Cooling in CH3NH3PbI3 Revealed by Femtosecond XUV Absorption

2019 ◽  
Author(s):  
Max A. Verkamp ◽  
Joshua Leveillee ◽  
Aastha Sharma ◽  
André Schleife ◽  
Josh Vura-Weis
Keyword(s):  
Quantitative Measurement ◽  
Transient Absorption ◽  
Extreme Ultraviolet ◽  
Transient Absorption Spectroscopy ◽  
Electron Dynamics ◽  
Hot Carrier ◽  
Phonon Bottleneck ◽  
Conduction Bands ◽  
Band Signal ◽  
Optical Transient

Femtosecond carrier cooling in the organohalide perovskite semiconductor CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> is measured using extreme ultraviolet (XUV) and optical transient absorption spectroscopy. XUV absorption between 44 eV and 58 eV measures transitions from the I 4d core to the valence and conduction bands and gives distinct signals for hole and electron dynamics. The core-to-valence-band signal directly maps the photoexcited hole distribution and provides a quantitative measurement of the hole temperature. The combination of XUV and optical probes reveals that upon excitation at 400 nm, the initial hole distribution is 3.5 times hotter than the electron distribution. At an initial carrier density of 1.4×10<sup>20</sup> cm<sup>-3</sup> both carriers are subject to a hot phonon bottleneck, but at 4.2×10<sup>19</sup> cm<sup>-3</sup> the holes cool to less than 1000 K within 400 fs. This result places significant constraints on the use of organohalide perovskites in hot-carrier photovoltaics.<br>

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

Science ◽  
2018 ◽  
Vol 361 (6397) ◽  
pp. 52-57 ◽  
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.

UV Two-Dimensional Transient Absorption Spectroscopy

2012 ◽  
Author(s):  
Gerald Auböck ◽  
Cristina Consani ◽  
Frank van Mourik ◽  
Majed Chergui
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Two Dimensional
Sign in / Sign up

Export Citation Format

Share Document