LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 8 of total 8

Search options

  1. Article ; Online: Giant Exciton Mott Density in Anatase TiO_{2}.

    Baldini, Edoardo / Palmieri, Tania / Dominguez, Adriel / Rubio, Angel / Chergui, Majed

    Physical review letters

    2020  Volume 125, Issue 11, Page(s) 116403

    Abstract: Elucidating the carrier density at which strongly bound excitons dissociate into a plasma of uncorrelated electron-hole pairs is a central topic in the many-body physics of semiconductors. However, there is a lack of information on the high-density ... ...

    Abstract Elucidating the carrier density at which strongly bound excitons dissociate into a plasma of uncorrelated electron-hole pairs is a central topic in the many-body physics of semiconductors. However, there is a lack of information on the high-density response of excitons absorbing in the near-to-mid ultraviolet, due to the absence of suitable experimental probes in this elusive spectral range. Here, we present a unique combination of many-body perturbation theory and state-of-the-art ultrafast broadband ultraviolet spectroscopy to unveil the interplay between the ultraviolet-absorbing two-dimensional excitons of anatase TiO_{2} and a sea of electron-hole pairs. We discover that the critical density for the exciton Mott transition in this material is the highest ever reported in semiconductors. These results deepen our knowledge of the exciton Mott transition and pave the route toward the investigation of the exciton phase diagram in a variety of wide-gap insulators.
    Language English
    Publishing date 2020-09-24
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.125.116403
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 58/153: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  2. Book ; Online: Giant exciton Mott density in anatase TiO2

    Baldini, Edoardo / Palmieri, Tania / Dominguez, Adriel / Rubio, Angel / Chergui, Majed

    2020  

    Abstract: Elucidating the carrier density at which strongly bound excitons dissociate into a plasma of uncorrelated electron-hole pairs is a central topic in the many-body physics of semiconductors. However, there is a lack of information on the high-density ... ...

    Abstract Elucidating the carrier density at which strongly bound excitons dissociate into a plasma of uncorrelated electron-hole pairs is a central topic in the many-body physics of semiconductors. However, there is a lack of information on the high-density response of excitons absorbing in the near-to-mid ultraviolet, due to the absence of suitable experimental probes in this elusive spectral range. Here, we present a unique combination of many-body perturbation theory and state-of-the-art ultrafast broadband ultraviolet spectroscopy to unveil the interplay between the ultraviolet-absorbing two-dimensional excitons of anatase TiO$_2$ and a sea of electron-hole pairs. We discover that the critical density for the exciton Mott transition in this material is the highest ever reported in semiconductors. These results deepen our knowledge of the exciton Mott transition and pave the route toward the investigation of the exciton phase diagram in a variety of wide-gap insulators.
    Keywords Condensed Matter - Materials Science ; Condensed Matter - Other Condensed Matter
    Subject code 530
    Publishing date 2020-07-20
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article ; Online: Exciton control in a room temperature bulk semiconductor with coherent strain pulses.

    Baldini, Edoardo / Dominguez, Adriel / Palmieri, Tania / Cannelli, Oliviero / Rubio, Angel / Ruello, Pascal / Chergui, Majed

    Science advances

    2019  Volume 5, Issue 11, Page(s) eaax2937

    Abstract: Controlling the excitonic optical properties of room temperature semiconductors using time-dependent perturbations is key to future optoelectronic applications. The optical Stark effect in bulk and low-dimensional materials has recently shown exciton ... ...

    Abstract Controlling the excitonic optical properties of room temperature semiconductors using time-dependent perturbations is key to future optoelectronic applications. The optical Stark effect in bulk and low-dimensional materials has recently shown exciton shifts below 20 meV. Here, we demonstrate dynamical tuning of the exciton properties by photoinduced coherent acoustic phonons in the cheap and abundant wide-gap semiconductor anatase titanium dioxide (TiO
    Language English
    Publishing date 2019-11-29
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2810933-8
    ISSN 2375-2548 ; 2375-2548
    ISSN (online) 2375-2548
    ISSN 2375-2548
    DOI 10.1126/sciadv.aax2937
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article ; Online: Mahan excitons in room-temperature methylammonium lead bromide perovskites.

    Palmieri, Tania / Baldini, Edoardo / Steinhoff, Alexander / Akrap, Ana / Kollár, Márton / Horváth, Endre / Forró, László / Jahnke, Frank / Chergui, Majed

    Nature communications

    2020  Volume 11, Issue 1, Page(s) 850

    Abstract: In a seminal paper, Mahan predicted that excitonic bound states can still exist in a semiconductor at electron-hole densities above the insulator-to-metal Mott transition. However, no clear evidence for this exotic quasiparticle, dubbed Mahan exciton, ... ...

    Abstract In a seminal paper, Mahan predicted that excitonic bound states can still exist in a semiconductor at electron-hole densities above the insulator-to-metal Mott transition. However, no clear evidence for this exotic quasiparticle, dubbed Mahan exciton, exists to date at room temperature. In this work, we combine ultrafast broadband optical spectroscopy and advanced many-body calculations to reveal that organic-inorganic lead-bromide perovskites host Mahan excitons at room temperature. Persistence of the Wannier exciton peak and the enhancement of the above-bandgap absorption are observed at all achievable photoexcitation densities, well above the Mott density. This is supported by the solution of the semiconductor Bloch equations, which confirms that no sharp transition between the insulating and conductive phase occurs. Our results demonstrate the robustness of the bound states in a regime where exciton dissociation is otherwise expected, and offer promising perspectives in fundamental physics and in room-temperature applications involving high densities of charge carriers.
    Language English
    Publishing date 2020-02-12
    Publishing country England
    Document type Journal Article
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-020-14683-5
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  5. Article: Interfacial Electron Injection Probed by a Substrate-Specific Excitonic Signature

    Baldini, Edoardo / Auböck Gerald / Chergui Majed / Oppermann Malte / Palmieri Tania / Pomarico Enrico / Rossi Thomas

    Journal of the American Chemical Society. 2017 Aug. 23, v. 139, no. 33

    2017  

    Abstract: Ultrafast interfacial electron transfer in sensitized solar cells has mostly been probed by visible-to-terahertz radiation, which is sensitive to the free carriers in the conduction band of the semiconductor substrate. Here, we demonstrate the use of ... ...

    Abstract Ultrafast interfacial electron transfer in sensitized solar cells has mostly been probed by visible-to-terahertz radiation, which is sensitive to the free carriers in the conduction band of the semiconductor substrate. Here, we demonstrate the use of deep-ultraviolet continuum pulses to probe the interfacial electron transfer, by detecting a specific excitonic transition in both N719-sensitized anatase TiO2 and wurtzite ZnO nanoparticles. Our results are compared to those obtained on bare nanoparticles upon above-gap excitation. We show that the signal upon electron injection from the N719 dye into TiO2 is dominated by long-range Coulomb screening of the final states of the excitonic transitions, whereas in sensitized ZnO it is dominated by phase-space filling. The present approach offers a possible route to detecting interfacial electron transfer in a broad class of systems, including other transition metal oxides or sensitizers.
    Keywords electron transfer ; nanoparticles ; screening ; semiconductors ; solar cells ; titanium dioxide ; zinc oxide
    Language English
    Dates of publication 2017-0823
    Size p. 11584-11589.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021%2Fjacs.7b06322
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 55/32: Show issues
    Z 7.3: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Article ; Online: Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO

    Baldini, Edoardo / Palmieri, Tania / Dominguez, Adriel / Ruello, Pascal / Rubio, Angel / Chergui, Majed

    Nano letters

    2018  Volume 18, Issue 8, Page(s) 5007–5014

    Abstract: The way nuclear motion affects electronic responses has become a very hot topic in materials science. Coherent acoustic phonons can dynamically modify optical, magnetic, and mechanical properties at ultrasonic frequencies, with promising applications as ... ...

    Abstract The way nuclear motion affects electronic responses has become a very hot topic in materials science. Coherent acoustic phonons can dynamically modify optical, magnetic, and mechanical properties at ultrasonic frequencies, with promising applications as sensors and transducers. Here, by means of ultrafast broadband deep-ultraviolet spectroscopy, we demonstrate that coherent acoustic phonons confined in anatase TiO
    Language English
    Publishing date 2018-07-26
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1530-6992
    ISSN (online) 1530-6992
    DOI 10.1021/acs.nanolett.8b01837
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  7. Article ; Online: Interfacial Electron Injection Probed by a Substrate-Specific Excitonic Signature.

    Baldini, Edoardo / Palmieri, Tania / Rossi, Thomas / Oppermann, Malte / Pomarico, Enrico / Auböck, Gerald / Chergui, Majed

    Journal of the American Chemical Society

    2017  Volume 139, Issue 33, Page(s) 11584–11589

    Abstract: Ultrafast interfacial electron transfer in sensitized solar cells has mostly been probed by visible-to-terahertz radiation, which is sensitive to the free carriers in the conduction band of the semiconductor substrate. Here, we demonstrate the use of ... ...

    Abstract Ultrafast interfacial electron transfer in sensitized solar cells has mostly been probed by visible-to-terahertz radiation, which is sensitive to the free carriers in the conduction band of the semiconductor substrate. Here, we demonstrate the use of deep-ultraviolet continuum pulses to probe the interfacial electron transfer, by detecting a specific excitonic transition in both N719-sensitized anatase TiO
    Language English
    Publishing date 2017-08-23
    Publishing country United States
    Document type Journal Article
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/jacs.7b06322
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 55/32: Show issues
    Z 7.3: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  8. Article: The LOUVRE Laboratory: State-of-the-Art Ultrafast Ultraviolet Spectroscopies for Molecular and Materials Science.

    Oppermann, Malte / Nagornova, Natalia S / Oriana, Aurelio / Baldini, Edoardo / Mewes, Lars / Bauer, Benjamin / Palmieri, Tania / Rossi, Thomas / van Mourik, Frank / Chergui, Majed

    Chimia

    2017  Volume 71, Issue 5, Page(s) 288–294

    Abstract: We describe the facilities for ultraviolet studies in the femtosecond to nanosecond time domain. These facilities consist of: i) a set-up for deep-ultraviolet spectroscopy in the 260-380 nm range in both pump and probe pulses for transient absorption/ ... ...

    Abstract We describe the facilities for ultraviolet studies in the femtosecond to nanosecond time domain. These facilities consist of: i) a set-up for deep-ultraviolet spectroscopy in the 260-380 nm range in both pump and probe pulses for transient absorption/reflectivity or two-dimensional spectroscopy studies; ii) a set-up for ultrafast fluorescence measurements with detection down to 300 nm. The capabilities of these set-ups are demonstrated by examples on molecular systems, biosystems, nanoparticles and solid materials.
    MeSH term(s) Animals ; Cytochromes c/chemistry ; Heart ; Horses ; Myoglobin/chemistry ; Spectrophotometry, Ultraviolet/instrumentation ; Time Factors ; Tryptophan/chemistry ; Ultraviolet Rays
    Chemical Substances Myoglobin ; Tryptophan (8DUH1N11BX) ; Cytochromes c (9007-43-6)
    Language English
    Publishing date 2017-05-31
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 1516-7
    ISSN 0009-4293
    ISSN 0009-4293
    DOI 10.2533/chimia.2017.288
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4.5: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top