The rise of organic magnetoresistance: materials and challenges

2017 ◽  
Vol 5 (23) ◽  
pp. 5572-5580 ◽  
Author(s):  
Marco Gobbi ◽  
Emanuele Orgiu
Keyword(s):  
Organic Semiconductors ◽  
Recent Progress ◽  
Organic Magnetoresistance ◽  
Magnetoresistive Effect

This paper provides a brief review of recent progress regarding the magnetoresistive effect observed in organic semiconductors.

Experimental Tests of Possible Mechanisms for the Organic Magnetoresistive Effect

2007 ◽  
Vol 1032 ◽  
Author(s):  
Tho Duc Nguyen ◽  
James Rybicki ◽  
Yugang Sheng ◽  
Markus Wohlgenannt
Keyword(s):  
Magnetic Field ◽  
Organic Semiconductors ◽  
Electrode Materials ◽  
Spin Dynamics ◽  
Experimental Tests ◽  
Triplet Exciton ◽  
Side Chain ◽  
Singlet Exciton ◽  
Organic Magnetoresistance ◽  
Magnetoresistive Effect

AbstractWe experimentally test three existing models of organic magnetoresistance (OMAR) which are all based on carrier spin dynamics. We first prove that hyperfine field originating from the hydrogen nuclei in organic materials is necessary for observing OMAR by studying C60 sandwich devices using several different electrode materials. We show that C60, unlike many other organic semiconductors, does not exhibit any intrinsic OMAR effect. However, we find that as soon as the carriers in C60 are brought in proximity with hydrogen-containing compounds, either in the form of a polymeric electrode, or side-chain substituents, a weak OMAR effect is observed. Next, we perform charge-induced absorption and electroluminescence spectroscopy in a polyfluorene organic magnetoresistive device. Our experiments allow us to measure the singlet exciton, triplet exciton and polaron densities in a live device under an applied magnetic field, and to distinguish between three models of OMAR. These models are based on different spin-dependent interactions, namely exciton formation, triplet exciton-polaron quenching and bipolaron formation. We show that the singlet exciton, triplet exciton and polaron densities and conductivity all increase with increasing magnetic field. Our data are inconsistent with the exciton formation and triplet-exciton polaron quenching models.

Recent progress in pyrazinoacenes containing nonbenzenoid rings: synthesis, properties and applications

2022 ◽  
Author(s):  
Fangyuan Kang ◽  
Jie Yang ◽  
Qichun Zhang
Keyword(s):  
Organic Semiconductors ◽  
Recent Progress ◽  
Organic Materials ◽  
Important Class ◽  
Great Progress ◽  
Synthesis Properties

Azaacenes have emerged as a new and important class of organic materials, and their synthetic strategies and applications as organic semiconductors have gained great progress in recent years. Generally, adopting...

scholarly journals Recent progress in the usage of tetrabromo-substituted naphthalenetetracarboxylic dianhydride as a building block to construct organic semiconductors and their applications

2020 ◽  
Vol 7 (19) ◽  
pp. 3001-3026 ◽  
Author(s):  
Cheng Zhang ◽  
Zongrui Wang ◽  
Hua Li ◽  
Jianmei Lu ◽  
Qichun Zhang
Keyword(s):  
Organic Semiconductors ◽  
Building Block ◽  
Recent Progress ◽  
Building Blocks

The recent synthetic strategies and significant applications of TBNDA and their derivatives as promising building blocks to construct π-expanded semiconductors have been carefully summarized in this review.

Recent Progress in the Synthesis of Benzo[b]thiophene

2020 ◽  
Vol 24 (19) ◽  
pp. 2256-2271
Author(s):  
Dau Xuan Duc
Keyword(s):  
Organic Semiconductors ◽  
Heterocyclic Compounds ◽  
Recent Progress ◽  
Medicinal Chemistry ◽  
Building Blocks ◽  
Intensive Research ◽  
Wide Range ◽  
Thiophene Derivatives ◽  
Anti Hiv ◽  
Aromatic Heterocyclic

: Benzo[b]thiophenes are aromatic heterocyclic compounds containing benzene and thiophene rings. This class of heterocycles is present in a large number of natural and non-natural compounds. Benzo[b]thiophene derivatives have a broad range of applications in medicinal chemistry such as antimicrobial, anticancer, antioxidant, anti-HIV and antiinflammatory activities. The use of benzo[b]thiophene derivatives in other fields has also been reported. Various benzo[b]thiophenes compounds have been employed as organic photoelectric materials, while several benzo[b]thiophenes have been used as organic semiconductors. Benzo[b]thiophenes have also been used as building blocks or intermediates for the synthesis of pharmaceutically important molecules. : Due to such a wide range of applicability, the synthesis of benzo[b]thiophene derivatives has attracted intensive research. Numerous mild and efficient approaches for the synthesis of benzo[b]thiophenes have been developed over the years. Different catalysts and substrates have been applied for benzo[b]thiophene synthesis. This review will focus on the studies in the construction of benzo[b]thiophene skeleton, which date back from 2012.

Recent Advance in 1-D Organic Semiconductors for Waveguide Applications

2019 ◽  
Vol 16 (3) ◽  
pp. 244-252 ◽  
Author(s):  
Rong Zhang ◽  
Xiaobei Jin ◽  
Xuwen Wen ◽  
Qi Chen
Keyword(s):  
Small Molecules ◽  
Organic Semiconductors ◽  
Recent Progress ◽  
Optoelectronic Properties ◽  
Size Reduction ◽  
One Dimensional ◽  
Good System ◽  
Ordered Nanostructures ◽  
Morphology Influence

One dimensional (1-D) micro-/nanostructures provide a good system to investigate the dependence of various properties on dimensionality and size reduction, especially in optoelectronic field. Organic conjugates including small molecules and polymers exhibit good optoelectronic properties and are apt to assemble into ordered nanostructures with well-defined shapes, tunable sizes and defect-free structures. In this review, we focus on recent progress of 1-D organic semiconductors for waveguide applications. Fabrication methods and materials of 1-D organic semiconductors are introduced. The morphology influence on the properties is also summarized.

Recent progress in the development of n-type organic semiconductors for organic field effect transistors

2017 ◽  
Vol 5 (34) ◽  
pp. 8654-8681 ◽  
Author(s):  
Jesse T. E. Quinn ◽  
Jiaxin Zhu ◽  
Xu Li ◽  
Jinliang Wang ◽  
Yuning Li
Keyword(s):  
Electron Transport ◽  
Organic Semiconductors ◽  
Field Effect ◽  
Recent Progress ◽  
Field Effect Transistors ◽  
Organic Field Effect Transistors ◽  
Major Progress

This article reviews recent major progress in the development of organic semiconductors as electron transport n-channel materials in organic field effect transistors (OFETs).

Materials for organic and hybrid inorganic/organic electronics

MRS Bulletin ◽  
2010 ◽  
Vol 35 (12) ◽  
pp. 1018-1027 ◽  
Author(s):  
Tobin J. Marks
Keyword(s):  
Organic Semiconductors ◽  
Soft Matter ◽  
Large Scale ◽  
Recent Progress ◽  
Gate Dielectrics ◽  
Atomic Level ◽  
Organizational Control ◽  
Oxide Semiconductors ◽  
Electronic Circuitry ◽  
Daunting Challenge

Materials scientists involved in synthesis are exceptionally skilled at designing and constructing individual molecules with the goal of introducing rationally tailored chemical and physical properties. However, the task of assembling such special molecules into organized, supramolecular structures with precise, nanometer-level organizational control to execute specific functions presents a daunting challenge. Soft and hard matter suitable for unconventional types of electronic circuitry represents a case in point and, in principal, offer capabilities not readily achievable with conventional silicon electronics. In this context, “unconventional” means circuitry that can span large areas, can be mechanically flexible and/or optically transparent, can be created by large-scale, high-throughput fabrication techniques, and has atomic-level tunability of properties. In the process of preparing, characterizing, and fabricating prototype devices with such materials, we learn many new things about the electronic and electrical properties of the materials and the interfaces between them. This account briefly overviews recent progress in three interconnected areas: (1) organic semiconductors for complementary π-electron circuits, (2) soft matter high-κ gate dielectrics for organic and inorganic electronics, and (3) metal-oxide semiconductors as components in such devices. Space limitations allow only touching upon selected highlights in this burgeoning field.

THE MANY FACES OF ORGANIC MAGNETORESISTANCE

SPIN ◽  
2011 ◽  
Vol 01 (01) ◽  
pp. 93-108 ◽  
Author(s):  
W. WAGEMANS ◽  
P. JANSSEN ◽  
A. J. SCHELLEKENS ◽  
F. L. BLOOM ◽  
P. A. BOBBERT ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Organic Semiconductors ◽  
Room Temperature ◽  
Magnetic Field Dependence ◽  
Essential Role ◽  
Hyperfine Fields ◽  
Spin Dephasing ◽  
Empirical Function ◽  
The Many ◽  
Organic Magnetoresistance

A surprisingly large "organic magnetoresistance" (OMAR) has been found in both polymers and small molecule organic semiconductors at relatively small applied magnetic fields and at room temperature. We review recent highlights in OMAR research and discuss some of the models that have been proposed to explain the effect. In all models spin dephasing due to hyperfine fields plays an essential role. In particular we focus on the characteristic magnetic field dependence, which is generally fitted with either a Lorentzian or a so-called non-Lorentzian function. The shape is determined by both the hyperfine fields and an additional broadening due to microscopic mechanisms, as described in the models. Within the present work, a new empirical function is introduced that captures the two effects separately and converges to the earlier introduced lineshapes in specific limits. Recently it has been demonstrated that an additional feature can be observed at ultra-small magnetic fields. This effect can be easily incorporated in our empirical approach by explicitly treating the limit in which hopping of carriers is no longer slow compared to spin precession in the hyperfine fields. Our approach is used to analyze several theoretical and experimental results. It is shown that experimentally observed trends can be well-understood and important parameters can be obtained from experimental data without prior knowledge about which model applies.

scholarly journals Light-induced magnetoresistance in solution-processed planar hybrid devices measured under ambient conditions

2017 ◽  
Vol 8 ◽  
pp. 1502-1507 ◽  
Author(s):  
Sreetama Banerjee ◽  
Daniel Bülz ◽  
Danny Reuter ◽  
Karla Hiller ◽  
Dietrich R T Zahn ◽  
...  
Keyword(s):  
Channel Length ◽  
Ambient Atmosphere ◽  
Ambient Conditions ◽  
Magnetoresistance Effect ◽  
Electron Hole ◽  
Solution Processed ◽  
Effect Transistor ◽  
Hybrid Devices ◽  
Organic Magnetoresistance ◽  
Magnetoresistive Effect

We report light-induced negative organic magnetoresistance (OMAR) measured in ambient atmosphere in solution-processed 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) planar hybrid devices with two different device architectures. Hybrid electronic devices with trench-isolated electrodes (HED-TIE) having a channel length of ca. 100 nm fabricated in this work and, for comparison, commercially available pre-structured organic field-effect transistor (OFET) substrates with a channel length of 20 µm were used. The magnitude of the photocurrent as well as the magnetoresistance was found to be higher for the HED-TIE devices because of the much smaller channel length of these devices compared to the OFETs. We attribute the observed light-induced negative magnetoresistance in TIPS-pentacene to the presence of electron–hole pairs under illumination as the magnetoresistive effect scales with the photocurrent. The magnetoresistance effect was found to diminish over time under ambient conditions compared to a freshly prepared sample. We propose that the much faster degradation of the magnetoresistance effect as compared to the photocurrent was due to the incorporation of water molecules in the TIPS-pentacene film.

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