Quantum Coherence Facilitates Efficient Charge Separation at a MoS₂/MoSe₂ van der Waals Junction

Nano Letters, Год журнала: 2016, Номер 16(3), С. 1996 - 2003

Опубликована: Фев. 16, 2016

Two-dimensional transition metal dichalcogenides (MX2, M = Mo, W; X S, Se) hold great potential in optoelectronics and photovoltaics. To achieve efficient light-to-electricity conversion, electron-hole pairs must dissociate into free charges. Coulomb interaction MX2 often exceeds the charge transfer driving force, leading one to expect inefficient separation at a heterojunction. Experiments defy expectation. Using time-domain density functional theory nonadiabatic (NA) molecular dynamics, we show that quantum coherence donor-acceptor delocalization facilitate rapid MoS2/MoSe2 interface. The is larger for electron than hole, resulting longer faster transfer. Stronger NA coupling higher acceptor state accelerate further. Both hole transfers are subpicosecond, which agreement with experiments. promoted primarily by out-of-plane Mo-X modes of acceptors. Lighter S atoms, compared Se, create electrons holes. relatively slow relaxation "hot" suggests long-distance bandlike transport, observed organic recombination notably across interface isolated MoS2 MoSe2, favoring long-lived separation. atomistic, studies provide valuable insights excitation dynamics two-dimensional dichalcogenides.

Язык: Английский

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High‐Performance Non‐Fullerene Polymer Solar Cells Based on a Pair of Donor–Acceptor Materials with Complementary Absorption Properties

Advanced Materials, Год журнала: 2015, Номер 27(45), С. 7299 - 7304

Опубликована: Окт. 13, 2015

A 7.3% efficiency non–fullerene polymer solar cell is realized by combining a large-bandgap PffT2-FTAZ-2DT with small-bandgap acceptor IEIC. The complementary absorption of donor and small-molecule responsible for the high-performance solar-cell device. This work provides important guidance to improve performance non-fullerene cells. As service our authors readers, this journal supporting information supplied authors. Such materials are peer reviewed may be re-organized online delivery, but not copy-edited or typeset. Technical support issues arising from (other than missing files) should addressed Please note: publisher content functionality any Any queries content) directed corresponding author article.

Язык: Английский

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Interfacial Charge Transfer States in Condensed Phase Systems

Annual Review of Physical Chemistry, Год журнала: 2016, Номер 67(1), С. 113 - 133

Опубликована: Март 16, 2016

Intermolecular charge transfer (CT) states at the interface between electron-donating (D) and electron-accepting (A) materials in organic thin films are characterized by absorption emission bands within optical gap of interfacing materials. CT efficiently generate carriers for some D–A combinations, others show high fluorescence quantum efficiencies. These properties exploited solar cells, photodetectors, light-emitting diodes. This review summarizes experimental theoretical work on electronic structure interfacial energy landscape condensed matter interfaces. Recent findings photogeneration recombination free via discussed, relations state optoelectronic device parameters clarified.

Язык: Английский

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Charge migration and charge transfer in molecular systems

Structural Dynamics, Год журнала: 2017, Номер 4(6)

Опубликована: Ноя. 1, 2017

The transfer of charge at the molecular level plays a fundamental role in many areas chemistry, physics, biology and materials science. Today, more than 60 years after seminal work R. A. Marcus, is still very active field research. An important recent impetus comes from ability to resolve ever faster temporal events, down attosecond time scale. Such high resolution now offers possibility unravel most elementary quantum dynamics both electrons nuclei that participate complex process transfer. This review covers research addresses following questions. Can we reconstruct migration across molecule on atomic length electronic scales? use strong laser fields control migration? temporally understand intramolecular dissociative ionization small molecules, transition-metal complexes conjugated polymers? tailor systems towards specific charge-transfer processes? What are scales steps liquids nanoparticles? Important new insights into each these topics, obtained state-of-the-art ultrafast spectroscopy and/or theoretical methods, summarized this review.

Язык: Английский

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Charge generation in polymer–fullerene bulk-heterojunction solar cells

Physical Chemistry Chemical Physics, Год журнала: 2014, Номер 16(38), С. 20291 - 20304

Опубликована: Янв. 1, 2014

Charge generation in organic solar cells is a fundamental yet heavily debated issue. This article gives balanced review of different mechanisms proposed to explain efficient charge polymer-fullerene bulk-heterojunction cells. We discuss the effect charge-transfer states, excess energy, external electric field, temperature, disorder materials, and delocalisation carriers on generation. Although general consensus has not been reached yet, recent findings, based both steady-state transient measurements, have significantly advanced our understanding this process.

Язык: Английский

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