Related Experiment Video
Updated: Jun 28, 2025
09:00
Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
9.9K
Structural Isomeric Effect on Spin Transport in Molecular Semiconductors
Tingting Yang1,2, Yang Qin1, Meng Wu1
1CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Advanced Materials (Deerfield Beach, Fla.)
|April 10, 2024
Summary
Structural isomers of molecular semiconductors exhibit different spin transport properties. Noncovalent-conformational locks in BDTIC enhance spin-orbit coupling, reducing spin lifetime, unlike ITIC.
Area of Science:
- Materials Science
- Organic Electronics
- Spintronics
Background:
- Molecular semiconductors (MSCs) offer long spin lifetimes due to weak spin-orbit coupling (SOC).
- SOC, influenced by elemental composition, is a primary cause of spin relaxation in MSCs.
- Molecular structure's impact on SOC is a key research area.
Purpose of the Study:
- To investigate the impact of molecular isomerism on spin transport in MSCs.
- To experimentally compare spin transport in ITIC and its structural isomer BDTIC.
- To elucidate the underlying mechanisms affecting spin lifetime in isomeric MSCs.
Main Methods:
- Experimental synthesis and characterization of ITIC and BDTIC films.
- Measurement of charge transport and molecular stacking.
- Electron paramagnetic resonance (EPR) spectroscopy.
- Density-functional-theory (DFT) calculations.
Main Results:
- Significantly different spin-transport performances observed between ITIC and BDTIC despite similar charge transport and molecular stacking.
- Identification of noncovalent-conformational locks (NCLs) in BDTIC structures.
- NCLs were found to enhance SOC, leading to decreased spin lifetime in BDTIC.
Conclusions:
- Structural isomerism significantly influences spin transport in MSCs.
- The presence of NCLs is a critical factor affecting SOC and spin lifetime.
- Future development of high-performance spin-transport MSCs must consider isomeric effects.
Keywords:
molecular spintronicsnoncovalent conformational locksspin lifetimespin transportstructural isomeric effectMore Related Videos
Related Concept Videos
01:03Atomic Nuclei: Nuclear Spin State Overview
938
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
938
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
1.0K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.0K
01:27π Electron Effects on Chemical Shift: Overview
1.1K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.1K
01:20Types of Semiconductors
589
Intrinsic semiconductors are highly pure materials with no impurities. At absolute zero, these semiconductors behave as perfect insulators because all the valence electrons are bound, and the conduction band is empty, disallowing electrical conduction. The Fermi level is a concept used to describe the probability of occupancy of energy levels by electrons at thermal equilibrium. In intrinsic semiconductors, the Fermi level is positioned at the midpoint of the energy gap at absolute zero. When...
589
02:34Structural Isomerism
19.2K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
19.2K
01:08NMR Spectroscopy: Spin–Spin Coupling
1.4K
The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved...
1.4K