Fachinformationsdienst BAUdigital

A platform for research: civil engineering, architecture and urbanism

    Carrier Multiplication in Transition Metal Dichalcogenides Beyond Threshold Limit

    New search for: Liu, Yuxiang
    New search for: Frauenheim, Thomas
    New search for: Yam, ChiYung

    Carrier multiplication (CM), multiexciton generation by absorbing a single photon, enables disruptive improvements in photovoltaic conversion efficiency. However, energy conservation constrains the threshold energy to at least twice bandgap (2 E g $ E_\text{g}$ ). Here, a below threshold limit CM in monolayer transition metal dichalcogenides (TMDCs) is reported. Surprisingly, CM is observed with excitation energy of only 1.75 E g $E_\text{g}$ due to lattice vibrations. Electron–phonon coupling (EPC) results in significant changes in electronic structures, which favors CM. Indeed, the strongest EPC in monolayer MoS2 leads to the most efficient CM among the studied TMDCs. For practical applications, chalcogen vacancies can further lower the threshold by introducing defect states within bandgap. In particular, for monolayer WS2, CM occurs with excitation energy as low as 1.51 E g $E_\text{g}$ . The results identify TMDCs as attractive candidate materials for efficient optoelectronic devices with the advantages of high photoconductivity and efficient CM.

    Access

    Download

    Access

    Download

    Page navigation

    Document information
    Similar titles

    Export, share and cite

    Carrier Multiplication in Transition Metal Dichalcogenides Beyond Threshold Limit

    New search for: Liu, Yuxiang
    New search for: Frauenheim, Thomas
    New search for: Yam, ChiYung

    Carrier multiplication (CM), multiexciton generation by absorbing a single photon, enables disruptive improvements in photovoltaic conversion efficiency. However, energy conservation constrains the threshold energy to at least twice bandgap (2 E g $ E_\text{g}$ ). Here, a below threshold limit CM in monolayer transition metal dichalcogenides (TMDCs) is reported. Surprisingly, CM is observed with excitation energy of only 1.75 E g $E_\text{g}$ due to lattice vibrations. Electron–phonon coupling (EPC) results in significant changes in electronic structures, which favors CM. Indeed, the strongest EPC in monolayer MoS2 leads to the most efficient CM among the studied TMDCs. For practical applications, chalcogen vacancies can further lower the threshold by introducing defect states within bandgap. In particular, for monolayer WS2, CM occurs with excitation energy as low as 1.51 E g $E_\text{g}$ . The results identify TMDCs as attractive candidate materials for efficient optoelectronic devices with the advantages of high photoconductivity and efficient CM.

    Access

    Download

    Carrier Multiplication in Transition Metal Dichalcogenides Beyond Threshold Limit

    New search for: Liu, Yuxiang
    New search for: Frauenheim, Thomas
    New search for: Yam, ChiYung

    Carrier multiplication (CM), multiexciton generation by absorbing a single photon, enables disruptive improvements in photovoltaic conversion efficiency. However, energy conservation constrains the threshold energy to at least twice bandgap (2 E g $ E_\text{g}$ ). Here, a below threshold limit CM in monolayer transition metal dichalcogenides (TMDCs) is reported. Surprisingly, CM is observed with excitation energy of only 1.75 E g $E_\text{g}$ due to lattice vibrations. Electron–phonon coupling (EPC) results in significant changes in electronic structures, which favors CM. Indeed, the strongest EPC in monolayer MoS2 leads to the most efficient CM among the studied TMDCs. For practical applications, chalcogen vacancies can further lower the threshold by introducing defect states within bandgap. In particular, for monolayer WS2, CM occurs with excitation energy as low as 1.51 E g $E_\text{g}$ . The results identify TMDCs as attractive candidate materials for efficient optoelectronic devices with the advantages of high photoconductivity and efficient CM.

    Access

    Download

    Access

    Download

    Page navigation

    Document information
    Similar titles

    Export, share and cite

    Document information
    Title:

    Carrier Multiplication in Transition Metal Dichalcogenides Beyond Threshold Limit

    Contributors:

    Liu, Yuxiang (author) / Frauenheim, Thomas (author) / Yam, ChiYung (author)

    Published in:

    Advanced Science ; 9

    Publication date:

    2022-11-01

    Size:

    8 pages

    ISSN:

    2198-3844

    DOI:

    https://doi.org/10.1002/advs.202203400

    Type of media:

    Article (Journal)

    Type of material:

    Electronic Resource

    Language:

    English

    Keywords:

    2D materials , carrier multiplication , chalcogen vacancy , non‐adiabatic molecular dynamics , time‐dependent density‐functional theory

    Similar titles

    Electronic properties of transition-metal dichalcogenides

    Kuc, Agnieszka / Heine, Thomas / Kis, Andras | British Library Online Contents | 2015

    Transition‐Metal Dichalcogenides for Photoelectrochemical Hydrogen Evolution Reaction

    Yunus, Rozan Mohamad / Salehmin, Mohd Nur Ikhmal / Rosman, Nurul Nabila | Wiley | 2020

    Computational study of phase engineered transition metal dichalcogenides heterostructures

    Ma, Jiachen / Zhang, Qiaoxuan / Yang, Jie et al. | British Library Online Contents | 2018

    Computational study of phase engineered transition metal dichalcogenides heterostructures

    Ma, Jiachen / Zhang, Qiaoxuan / Yang, Jie et al. | British Library Online Contents | 2018

    Synthesis and structure of two-dimensional transition-metal dichalcogenides

    Shi, Yumeng / Zhang, Hua / Chang, Wen-Hao et al. | British Library Online Contents | 2015

    Back to top