Spin dynamic study on the electric field dependence of carrier generation.

The journal of physical chemistry. B · 2005 · Mixed · Low evidence

← Research stream

MixedLow evidencePaper 3572

Study snapshot

PublicationThe journal of physical chemistry. B · 2005

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

Using an acceptor-doped poly(N-vinylcarbazole) film, the magnetic field effect (MFE) on the generation efficiency of photoinduced charge was measured under various electric fields in order to clarify how the applied electric field affects the elementary processes in the photocarrier generation in photoconductive polymeric molecular solids. The external magnetic field influenced the electron spin dynamics among the geminate electron-hole pairs within a scale of a few nanometers and decreased the photocarrier generation efficiency. The observed MFE due to a hyperfine mechanism was almost independent of the electric field. By employing the stochastic Liouville equations based on a one-dimensional lattice model, we performed some model calculations for the dissociation, hopping, and recombination rate dependence of MFE on the generation efficiency. From a comparison between the observed and calculated MFE, it was concluded that the electric field affects the dissociation more than the hopping and the recombination. This coincides with the concepts in the Onsager model that is used to analyze the electric field dependence of carrier generation efficiency so far. The one-dimensional lattice model is a proper model for the carrier generation in polymeric molecular solids, which is qualitatively consistent with the Onsager model except for the long-range hole jump.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro

Effect directionmixed

PopulationNot supplied

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthLowConfidence: 66% · Peer reviewed: yes

Main findings

In an acceptor-doped poly(N-vinylcarbazole) film, an external magnetic field affected electron spin dynamics among geminate electron-hole pairs and decreased photocarrier generation efficiency. The observed magnetic field effect attributed to a hyperfine mechanism was reported to be almost independent of the applied electric field. Model calculations (stochastic Liouville equations with a one-dimensional lattice model) suggested the electric field affects dissociation more than hopping and recombination.

Outcomes measured

magnetic field effect (MFE) on generation efficiency of photoinduced charge/photocarrier generation efficiency
electron spin dynamics among geminate electron-hole pairs
electric field dependence of dissociation/hopping/recombination processes (modeling)

Limitations

In vitro polymer film system; findings may not generalize beyond the specific material and experimental conditions.
Exposure characteristics of the magnetic field (e.g., strength, waveform/frequency) are not provided in the abstract.
Electric field parameters and measurement details are not provided in the abstract.
Includes model-based inference (one-dimensional lattice model; comparison to Onsager model), which may depend on modeling assumptions.

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": null,
    "source": "external magnetic field",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "magnetic field effect (MFE) on generation efficiency of photoinduced charge/photocarrier generation efficiency",
    "electron spin dynamics among geminate electron-hole pairs",
    "electric field dependence of dissociation/hopping/recombination processes (modeling)"
  ],
  "main_findings": "In an acceptor-doped poly(N-vinylcarbazole) film, an external magnetic field affected electron spin dynamics among geminate electron-hole pairs and decreased photocarrier generation efficiency. The observed magnetic field effect attributed to a hyperfine mechanism was reported to be almost independent of the applied electric field. Model calculations (stochastic Liouville equations with a one-dimensional lattice model) suggested the electric field affects dissociation more than hopping and recombination.",
  "effect_direction": "mixed",
  "limitations": [
    "In vitro polymer film system; findings may not generalize beyond the specific material and experimental conditions.",
    "Exposure characteristics of the magnetic field (e.g., strength, waveform/frequency) are not provided in the abstract.",
    "Electric field parameters and measurement details are not provided in the abstract.",
    "Includes model-based inference (one-dimensional lattice model; comparison to Onsager model), which may depend on modeling assumptions."
  ],
  "evidence_strength": "low",
  "confidence": 0.66,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "poly(N-vinylcarbazole)",
    "acceptor-doped film",
    "magnetic field effect",
    "electron spin dynamics",
    "geminate electron-hole pairs",
    "photocarrier generation",
    "hyperfine mechanism",
    "electric field dependence",
    "stochastic Liouville equations",
    "Onsager model",
    "one-dimensional lattice model"
  ],
  "suggested_hubs": []
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1021/jp044475e
PubMed: 16851823

Read the original paper →

Related papers

← Back to the Research Library