Hyperfine interaction vs. spin–orbit coupling in organic semiconductors

“…SOC and HFI are two main factors that affect spin dependent scattering. SOC is the coupling between orbital angular momentum and spin momentum; the strength of SOC is proportional to Z 4 (Z is the atomic number) [ 87 , 88 , 89 , 90 ]. Organic materials mainly consisting of C, H, O and N elements possess much lower atomic numbers than their inorganic counterparts; therefore, OSCs are expected to present a weaker spin orbit coupling.…”

Section: Traditional Organic Spin Valvesmentioning

confidence: 99%

“…The importance of HFI on MR response has been underlined in both theories and experiments [ 96 , 97 , 98 , 99 ]. HFI is the spin-spin interaction between nucleus spin and electron spin, which is principally affected by polarized hydrogen nuclei and other nuclear atoms in OSCs [ 90 , 99 ]. Nguyen et al studied the magnetotransport in both H 18 Alq 3 (protonated) and D 18 Alq 3 (deuterated)-based spin valves [ 98 ].…”

Section: Traditional Organic Spin Valvesmentioning

confidence: 99%

Magnetoresistance Effect and the Applications for Organic Spin Valves Using Molecular Spacers

et al. 2018

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Organic spin devices utilizing the properties of both spin and charge inherent in electrons have attracted extensive research interest in the field of future electronic device development. In the last decade, magnetoresistance effects, including giant magetoresistance and tunneling magnetoresistance, have been observed in organic spintronics. Significant progress has been made in understanding spin-dependent transport phenomena, such as spin injection or tunneling, manipulation, and detection in organic spintronics. However, to date, materials that are effective for preparing organic spin devices for commercial applications are still lacking. In this report, we introduce basic knowledge of the fabrication and evaluation of organic spin devices, and review some remarkable applications for organic spin valves using molecular spacers. The current bottlenecks that hinder further enhancement for the performance of organic spin devices is also discussed. This report presents some research ideas for designing organic spin devices operated at room temperature.

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“…Relative to the 1960s, when El-Sayed published his famous rule about 1 nπ * ↔ 3 ππ * and 3 nπ * ↔ 1 ππ * transitions, a great deal more is known today about SOC in photoexcited states, and several electronic structure packages can routinely compute SOC tensors today. That being said, far less is known about the impact of hyperfine coupling, though there has been some recent work exploring HFC-promoted ISC in planar aromatic hydrocarbons and organic semiconductors. , …”

Section: Introductionmentioning

confidence: 99%

Spin–Orbit versus Hyperfine Coupling-Mediated Intersystem Crossing in a Radical Pair

et al. 2023

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While spin–orbit coupling (SOC) is typically the dominant interaction that couples singlet and triplet states within individual chromophores, hyperfine coupling (HFC) becomes important in multichromophoric systems, particularly in relation to the radical pair mechanism. Here, we use TD-DFT to calculate the spin–orbit coupling and hyperfine coupling between the first singlet and triplet charge transfer states of the radical pair 2Pyrene– and 2 N,N-dimethylaniline+. We show that, as the intermolecular donor–acceptor distance grows, SOC decays to zero (as one would expect) because singlet and triplet states are characterized by identical orbitals in space, while the HFC remains comparatively constant. The switching region occurs around 4 Å, beyond which HFC dominates over SOC as far as defining the rate of intersystem crossing (ISC).

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Hyperfine interaction vs. spin–orbit coupling in organic semiconductors

Abstract: We report experimental and theoretical studies on hyperfine interaction vs. spin–orbit coupling in a thin film of organic semiconductor poly[9,9-di-n-hexylfluorenyl-2,7-diyl] and the dramatic influence of doping the PFO with bis[2-(2′-benzothienyl)pyridinato-N,C3′]Ir(acac).

Cited by 16 publications

References 20 publications

The influence of electron transport layer on magnetic-field effect of organic light-emitting diode

The influence of electron transport layer on magnetic-field effect of organic light-emitting diode

Magnetoresistance Effect and the Applications for Organic Spin Valves Using Molecular Spacers

Spin–Orbit versus Hyperfine Coupling-Mediated Intersystem Crossing in a Radical Pair

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