Interpreting transient photocurrents as a signature of the density of states distribution

the profound importance of the short-time decay

S. Grabtchak, C. Main, S. Reynolds

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    6 Citations (Scopus)

    Abstract

    We present a study exploring the fidelity of recovery of the density of states from transient photocurrents for different distributions of traps based on computer simulation of transient photocurrent decay (TPC). The most important result of the work is that much of the information on the form of the density of states (DOS) over an energy range of up to 0.5 eV depth, is contained in the detailed form of the initial decay of the photocurrent on a timescale <10-10 s in which we might expect only the shallowest traps to have an affect. To illustrate this point, we demonstrate that substantially different DOS distributions (exponential, Gaussian, rectangular) can be made to give apparently identical TPC decays over several orders of magnitude of time after an initial trapping phase in which there are only small differences in the shape of the response. Recombination effects may also be included. Nevertheless, using a Fourier transform TPC analytical method we can make a distinction between such DOS distributions, provided the short-time initial decay is included.
    Original languageEnglish
    Pages (from-to)362-366
    Number of pages5
    JournalJournal of Non-Crystalline Solids
    Volume266
    DOIs
    Publication statusPublished - 2000

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    Photocurrents
    photocurrents
    signatures
    decay
    traps
    Fourier transforms
    Recovery
    computerized simulation
    recovery
    trapping
    Computer simulation

    Keywords

    • D140, C240, T340, P180, T280

    Cite this

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    title = "Interpreting transient photocurrents as a signature of the density of states distribution: the profound importance of the short-time decay",
    abstract = "We present a study exploring the fidelity of recovery of the density of states from transient photocurrents for different distributions of traps based on computer simulation of transient photocurrent decay (TPC). The most important result of the work is that much of the information on the form of the density of states (DOS) over an energy range of up to 0.5 eV depth, is contained in the detailed form of the initial decay of the photocurrent on a timescale <10-10 s in which we might expect only the shallowest traps to have an affect. To illustrate this point, we demonstrate that substantially different DOS distributions (exponential, Gaussian, rectangular) can be made to give apparently identical TPC decays over several orders of magnitude of time after an initial trapping phase in which there are only small differences in the shape of the response. Recombination effects may also be included. Nevertheless, using a Fourier transform TPC analytical method we can make a distinction between such DOS distributions, provided the short-time initial decay is included.",
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    author = "S. Grabtchak and C. Main and S. Reynolds",
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    TY - JOUR

    T1 - Interpreting transient photocurrents as a signature of the density of states distribution

    T2 - the profound importance of the short-time decay

    AU - Grabtchak, S.

    AU - Main, C.

    AU - Reynolds, S.

    PY - 2000

    Y1 - 2000

    N2 - We present a study exploring the fidelity of recovery of the density of states from transient photocurrents for different distributions of traps based on computer simulation of transient photocurrent decay (TPC). The most important result of the work is that much of the information on the form of the density of states (DOS) over an energy range of up to 0.5 eV depth, is contained in the detailed form of the initial decay of the photocurrent on a timescale <10-10 s in which we might expect only the shallowest traps to have an affect. To illustrate this point, we demonstrate that substantially different DOS distributions (exponential, Gaussian, rectangular) can be made to give apparently identical TPC decays over several orders of magnitude of time after an initial trapping phase in which there are only small differences in the shape of the response. Recombination effects may also be included. Nevertheless, using a Fourier transform TPC analytical method we can make a distinction between such DOS distributions, provided the short-time initial decay is included.

    AB - We present a study exploring the fidelity of recovery of the density of states from transient photocurrents for different distributions of traps based on computer simulation of transient photocurrent decay (TPC). The most important result of the work is that much of the information on the form of the density of states (DOS) over an energy range of up to 0.5 eV depth, is contained in the detailed form of the initial decay of the photocurrent on a timescale <10-10 s in which we might expect only the shallowest traps to have an affect. To illustrate this point, we demonstrate that substantially different DOS distributions (exponential, Gaussian, rectangular) can be made to give apparently identical TPC decays over several orders of magnitude of time after an initial trapping phase in which there are only small differences in the shape of the response. Recombination effects may also be included. Nevertheless, using a Fourier transform TPC analytical method we can make a distinction between such DOS distributions, provided the short-time initial decay is included.

    KW - D140, C240, T340, P180, T280

    U2 - 10.1016/S0022-3093(99)00728-0

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    JO - Journal of Non-Crystalline Solids

    JF - Journal of Non-Crystalline Solids

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