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In micellar catalysis, one uses aggregates formed by surfactants as nanoreactors for performing chemical reactions. A special class of tailor‐made surfactants containing catalytically active sites opens new perspectives in micellar catalysis. Little is known about the combination of such surfactants with photocatalysis. Molecular semiconductors are presented, which simultaneously have amphiphilic properties and are made of a hydrophilic fullerenol head group attached to dye molecules as the hydrophobic entity. The first generation of those surfactants produces reactive oxygen species (ROS) when exposed to light in the UV/Vis range. The concept of the current paper is that one can drive the photocatalytic process also using low‐energy photons in the near‐infrared region. For this purpose, NIR‐active dye molecules were selected and attached to the fullerenol head. It is shown that a fullerenol ‐ aminostilbene compound representing the second generation of semiconductor surfactants fulfills all requirements. It forms aggregates in water that are catalytically active. Moreover, two‐photon experiments with λ=780 nm were performed, indicating successful ROS production and, thus, photocatalytic activity. [ABSTRACT FROM AUTHOR]

Molecular semiconductors (MSCs), characterized by a longer spin lifetime than most of other materials due to their weak spin relaxation mechanisms, especially at room temperature, together with their abundant chemical tailorability and flexibility, are regarded as promising candidates for spintronic applications. Molecular spintronics, as an emerging subject that utilizes the unique properties of MSCs to study spin-dependent phenomena and properties, has attracted wide attention. In molecular spintronic devices, MSCs play the role as medium for information transport, process, and storage, in which the efficient spin inject–transport process is the prerequisite. Herein, we focus mainly on summarizing and discussing the recent advances in theoretical principles towards spin transport of MSCs in terms of the injection of spin-polarized carriers through the ferromagnetic metal/MSC interface and the subsequent transport within the MSC layer. Based on the theoretical progress, we cautiously present targeted design strategies of MSCs that contribute to the optimization of spin-transport efficiency and give favorable approaches to exploring accessional possibilities of spintronic materials. Finally, challenges and prospects regarding current spin transport are also presented, aiming to promote the development and application of the rosy and energetic field of molecular spintronics. [ABSTRACT FROM AUTHOR]

Attaining compact energy storage under extreme temperature conditions is of paramount importance in the development of advanced dielectric materials. The polymer composite approach has proved effective towards this goal, and addressing the correlation between filler distribution and electrical properties is foremost in designing composite dielectrics, especially in multifiller systems. Here, the design of a bi‐gradient polymer composite dielectric using an integrated framework based on the phase field model is reported. This framework can predict the charge‐inhibiting behavior of composite dielectrics, which is a key factor impacting the high‐temperature capacitive performance but unfortunately is ignored in conventional phase field models. It is found that due to the traps provided by the functional organic fillers, more carriers are trapped near the electrodes and weaken the electric field, thus significantly suppressing the breakdown initialization process. An interpenetrating gradient structure is designed rationally and synthesized experimentally, which exhibits concurrent high energy density (5.51 J cm−3) and high charge‐discharge efficiency (90%) up to 200 °C. This work provides a strategy to predict the high‐temperature energy storage performance of polymer composites containing charge‐inhibiting components and helps broaden the scope of data‐driven materials design based on phase‐field modeling. [ABSTRACT FROM AUTHOR]

Abstract Attaining compact energy storage under extreme temperature conditions is of paramount importance in the development of advanced dielectric materials. The polymer composite approach has proved effective towards this goal, and addressing the correlation between filler distribution and electrical properties is foremost in designing composite dielectrics, especially in multifiller systems. Here, the design of a bi‐gradient polymer composite dielectric using an integrated framework based on the phase field model is reported. This framework can predict the charge‐inhibiting behavior of composite dielectrics, which is a key factor impacting the high‐temperature capacitive performance but unfortunately is ignored in conventional phase field models. It is found that due to the traps provided by the functional organic fillers, more carriers are trapped near the electrodes and weaken the electric field, thus significantly suppressing the breakdown initialization process. An interpenetrating gradient structure is designed rationally and synthesized experimentally, which exhibits concurrent high energy density (5.51 J cm−3) and high charge‐discharge efficiency (90%) up to 200 °C. This work provides a strategy to predict the high‐temperature energy storage performance of polymer composites containing charge‐inhibiting components and helps broaden the scope of data‐driven materials design based on phase‐field modeling.

Under long‐term thermal stress, the decomposition of organic‐inorganic hybrid perovskite is a big challenge to realize stable and efficient perovskite solar cells (PSCs). Thereby, it is of pivotal importance to engineer an organic hole transport layer, which is featured not only by an excellent hole conduction but also by a high glass transition temperature. Here, a solution‐processible molecular semiconductor (T5H‐EP‐BMCA) is reported. The air‐doped composite of T5H‐EP‐BMCA presents a hole density of 6.5 × 1017 cm–3, a space‐charge‐limited current hole mobility of 5.1 × 10–4 cm2 V–1 s–1, and a direct‐current electrical conductivity of 30.6 µS cm–1. Moreover, the conductive composite owns a high glass transition temperature of 165 °C, a heat‐resistant morphology, and low gas permeability coefficients. These joint attributes allow for the fabrication of 21.0%‐efficiency, 85 °C‐durable PSC by controlling the thermal decomposition of perovskite. [ABSTRACT FROM AUTHOR]

Due to the extremely low intrinsic carrier density and disordered nature of organic semiconductor thin films, unintentional or intentional chemical doping is inevitable for sufficiently high carrier density and charge mobility unless charges are either injected from appropriate electrodes or by photoexcitation. However, doping often results in a reduction in thermal tolerance. The charge transport layers for thermostable perovskite solar cells (PSCs) need to possess a heat‐resistant morphology and to suppress the diffusion of volatile species. Here the authors report a molecular semiconductor with a molecular mass of >2000 Daltons but free of any flexible side chains. Its air‐doped composite with thermally stable acid salt exhibits an electrical conductivity of over 50 μS cm−1 and a glass transition temperature of 142 °C. Molecular dynamics simulations reveal that molecules and ions in this composite do not experience significant translational motion even at 150 °C. These unusual features allow for the fabrication of 21.5%‐efficiency PSCs that can withstand 200 h at 100 °C. [ABSTRACT FROM AUTHOR]

• Novel carbazole and diketopyrrolopyrrole-based molecule (CAR-TzDPP) was synthesized. • A comparative study between the carbazole and triazatruxene endcaps was conducted. • Experimental and theoretical properties (DFT and TD-DFT) were found in good agreement. • Two-dimensional (2D) ambipolar charge transport was observed in CAR-TzDPP thin film. • Triazatruxene-based molecule (TAT-TzDPP) provides 3D unipolar charge transport. In this work, we describe the design and synthesis of a novel soluble conjugated molecule, CAR-TzDPP , consisting of a central diketopyrrolopyrrole core (DPP) connected to carbazole endcaps through thiazole rings. To evaluate its properties, a triazatruxene-based molecule (TAT-TzDPP) was used as a model for comparison. The electrochemical and the in-solution optical properties are in good agreement with those obtained from DFT calculations. However, the thin-film self-assemblies of CAR-TzDPP exhibited distinct differences, forming a more standard crystalline structure including insulating side-chains layers that disallowed side interactions between aromatic rings. This resulted in a reduced charge transport ability to a two-dimensional (2D) ambipolar charge transport in CAR-TzDPP , compared to the nearly isotropic unipolar charge transport in TAT-TzDPP. Despite this, CAR-TzDPP can be considered a viable alternative for device configurations requiring semiconducting pathways aligned in the substrate plane due to its simplified and high yield synthesis route, ease of processing, and reliable charge mobility in OFETs. This research highlights the significance of molecular units in small semiconducting organic molecules, not only in terms of their individual optoelectronic properties but also in terms of their self-assembly capabilities, which ultimately influence their charge transport properties. [Display omitted] [ABSTRACT FROM AUTHOR]

Organized nano‐ and microstructures of molecular semiconductors display interesting optical and photonic properties, and enhanced charge carrier mobilities, as compared to disordered thin films. However, known directed‐growth and self‐organization strategies cannot create structured molecular heterojunctions and cannot be practically incorporated into existing device fabrication routines to create large‐area optoelectronic devices. Here, an ultrathin (<2 nm) seed layer of the compound coronene creates 1D nanostructures of an electron‐transporting molecule (IFD) is shown, which possesses an intrinsic proclivity to form disordered thin films in the absence of the seed layer. It is revealed that nanostructured IFD films exhibit enhanced light absorption and emission, and greater electron mobilities, as compared to amorphous counterparts. This seed layer strategy creates uniform IFD nanowires over large areas of up to 18 mm2 at low processing temperatures. Notably, the coronene seed layer creates IFD nanowires when applied over either oxide surfaces or predeposited organic layers, meaning that this structuring approach can be integrated into diode manufacturing routines to realize large‐area flexible optoelectronic devices. Flexible organic light‐emitting diodes and fullerene‐free organic solar cells containing IFD nanowires in the photoactive layer to demonstrate that molecular nanostructures can lead to robust, large‐area device arrays on flexible substrates being fabricated. [ABSTRACT FROM AUTHOR]

Gas sensors based on ambipolar materials offer significant advantages in reducing the size of the analytical system and enhancing its efficiency. Here, bilayer heterojunction devices are constructed using different octafluorinated phthalocyanine complexes, with Zn and Co as metal centers, combined with a lutetium bisphthalocyanine complex (LuPc 2 ). Stable p-type behavior is observed for the ZnF 8 Pc/LuPc 2 device under both electron-donating (NH 3 ) and -oxidizing (NO 2 and O 3 ) gaseous species, while the CoF 8 Pc/LuPc 2 device exhibits n-type behavior under reducing gases and p-type behavior under oxidizing gases. The nature of majority of the charge carriers of Co-based devices varies depending on the nature of target gases, displaying an ambipolar behavior. Both heterojunction devices demonstrate stable and observable response toward all three toxic gases in the sub-ppm range. Remarkably, the Co-based device is highly sensitive toward ammonia with a limit of detection (LOD) of 200 ppb, whereas the Zn-based device demonstrates exceptional sensitivity toward oxidizing gases, with excellent LOD values of 4.9 and 0.75 ppb toward NO 2 and O 3 , respectively, which makes it one of the most effective organic heterojunction sensors reported so far for oxidizing gases.

Efficient and robust n-i-p perovskite solar cells necessitate superior organic hole-transport materials with both mechanical and electronic prowess. Deciphering the structure-property relationship of these materials is crucial for practical perovskite solar cell applications. Through direct arylation, two high glass transition temperature molecular semiconductors, DBC-ETPA (202 °C) and TPE-ETPA (180 °C) are synthesized, using dibenzo[g,p]chrysene (DBC) and 1,1,2,2-tetraphenylethene (TPE) tetrabromides with triphenylene-ethylenedioxythiophene-dimethoxytriphenylamine (ETPA). In comparison to spiro-OMeTAD, both semiconductors exhibit shallower HOMO energy levels, resulting in increased hole densities (generated by air oxidation doping) and accelerated hole extraction from photoexcited perovskite. Experimental and theoretical studies highlight the more rigid DBC core, enhancing hole mobility due to reduced reorganization energy and lower energy disorder. Importantly, DBC-ETPA possesses a higher cohesive energy density, leading to lower ion diffusion coefficients and higher Young's moduli. Leveraging these attributes, DBC-ETPA is employed as the primary hole-transport layer component, yielding perovskite solar cells with an average efficiency of 24.5%, surpassing spiro-OMeTAD reference cells (24.0%). Furthermore, DBC-ETPA-based cells exhibit superior operational stability and 85 °C thermal storage stability., (© 2024 Wiley‐VCH GmbH.)

The design and synthesis of two semiconducting bis (4‐ethynyl‐bridging 1, 8‐naphthalimide) bolaamphiphiles (BENI‐COO− and BENI‐NH3+) to fabricate supramolecular metal–insulator–semiconductor (MIS) nanostructures for biomimetic hydrogen evolution under visible light irradiation is presented. A H2 evolution rate of ca. 3.12 mmol g−1⋅h−1 and an apparent quantum efficiency (AQE) of ca. 1.63 % at 400 nm were achieved over the BENI‐COO−‐NH3+‐Ni MIS photosystem prepared by electrostatic self‐assembly of BENI‐COO− with the opposite‐charged DuBois‐Ni catalysts. The hot electrons of photoexcited BENI‐COO− nanofibers were tunneled to the molecular Ni collectors across a salt bridge and an alkyl region of 2.2–2.5 nm length at a rate of 6.10×108 s−1, which is five times larger than the BENI‐NH3+ nanoribbons (1.17×108 s−1). The electric field benefited significantly the electron tunneling dynamics and compensated the charge‐separated states insufficient in the BENI‐COO− nanofibers. [ABSTRACT FROM AUTHOR]

Controlled self‐organization of organic semiconductor molecules into specifically desired architectures on substrates of interest is one of the most imperative challenges faced in the fabrication of high‐performance organic electronic devices. Herein, we report the self‐organization of a star‐shaped molecule FDT‐8 into a highly favored structure, namely, a vertical stack. Thermal annealing of films of FDT‐8 deposited on PEDOT: PSS coated ITO substrates was observed to assist the organization of the molecules into columnar stacks. A significant enhancement in the hole (≈50‐fold) and the electron (≈13‐fold) carrier mobility was observed in single‐carrier devices upon thermal annealing that could be attributed to the aforementioned self‐organization. The ability of these molecules to spontaneously self‐organize was utilized to fabricate bilayer light‐emitting devices. [ABSTRACT FROM AUTHOR]

In this account, we discuss the common molecular features and the related chemistry concepts across several different areas of organic electronics, including molecular semiconductors and single-molecule junctions. Despite seemingly diverse charge transport mechanisms and device set-ups, various molecular electronics systems can benefit from the same fundamental principles of physical organic chemistry, based upon the electronic structure and geometry of their molecular building blocks and the intermolecular interactions between them. This is not an exhaustive review of organic electronics, but rather a focused account of primarily our own recent efforts aimed at developing a unified approach to understanding and designing conductive molecular species for diverse electronic applications.

We revisit a series of trifluoromethylated C 70 (CF 3 ) n compounds with n = 2–12 to provide a comprehensive comparative characterization thereof by means of a combination of physico-chemical methods. X-ray diffraction studies, including first structural determinations of the major isomers of C 70 (CF 3 ) 2 , C 70 (CF 3 ) 4 , and the third most abundant isomer of C 70 (CF 3 ) 8 as co-crystals with octaethylporphyrin Ni(II), produce accurate CF 3 group rotation angles and intergroup F⋯F distances that enable more reliable 19 F NMR signal assignment based on the through-space J FF spin-spin coupling relation to the F⋯F distances. Cyclic voltammetry measurements were performed in a potential range that covers oxidation on the one end and reduction to tri- or tetraanionic states on the other. It was demonstrated that the CF 3 addition patterns have marked effects on the redox potentials. A consistent set of the experimental HOMO energy values of the C 70 (CF 3 ) n molecules is reported for the first time in complement to the LUMO data, and the both sets of results were found to demonstrate good correlation with quantum-chemical DFT predictions. Most of the compounds exhibit electrochemically reversible one-electron reductions up to trianionic (sometimes even tetraanionic) state, a notable exception being C 70 (CF 3 ) 10 with irreversibility of its very first reduction. Bulk electrolysis of C 70 (CF 3 ) 12 at its 4-th reduction potential identifies CF 3 detachment as the most likely cause of the observed irreversible processes yielding C 70 (CF 3 ) 11 − anions as was identified by means of MALDI MS. [ABSTRACT FROM AUTHOR]

Abundant spin-related phenomena that originate from interfaces between ferromagnetic electrodes and molecular semiconductors have greatly enriched research in spintronics, and they are considered promising for realizing novel spintronic functionalities in the future. However, despite great effort, the interfacial effect cannot be precisely controlled to achieve steady and predictable functions, especially at room temperature, and this has gradually become a significant bottleneck in the development of molecular spintronics. In this study, an innovative spin-filtering-competition mechanism is proposed to continuously modulate the interfacial effect in molecular spin valves at room temperature. To form this novel mechanism, the original spin-filtering effect from pure cobalt competes with the newly generated one, which is induced by the bonding effect between cobalt and lithium fluoride. Subsequently, by precisely controlling competition through lithium fluoride coverage on the cobalt surface, continuous modulation of the spin-injection process can be successfully achieved at room temperature. Spin polarization of the injected current and magnetoresistance effect can be actively controlled or their sign can be completely reversed through this novel mechanism. This study provides an innovative approach and theory for precisely controlling spin-related interfacial effects, which may further promote the scientific and technological development of spintronics., (© 2023 Wiley-VCH GmbH.)

Due to the nonperiodic nature of charge transport in disordered systems, generating insight into static charge transport networks, as well as analyzing the network dynamics, can be challenging. Here, we apply time-dependent network analysis to scrutinize the charge transport networks of two representative molecular semiconductors: a rigid n-type molecule, perylenediimide, and a flexible p-type molecule, bBDT(TDPP)2. Simulations reveal the relevant timescale for local transfer integral decorrelation to be ~100 fs, which is shown to be faster than that of a crystalline morphology of the same molecule. Using a simple graph metric, global network changes are observed over timescales competitive with charge carrier lifetimes. These insights demonstrate that static charge transport networks are qualitatively inadequate, whereas average networks often overestimate network connectivity. Finally, a simple methodology for tracking dynamic charge transport properties is proposed. [ABSTRACT FROM AUTHOR]

In solution-processable small molecule semiconductors, the extent of charge carrier wavefunction localization induced by dynamic disorder can be probed spectroscopically as a function of temperature using charge modulation spectroscopy (CMS). Here, it is shown based on combined field-effect transistor and CMS measurements as a function of temperature that in certain molecular semiconductors, such as solution-processible pentacene, charge carriers become trapped at low temperatures in environments in which the charges become highly localized on individual molecules, while in some other molecules the charge carrier wavefunction can retain a degree of delocalization similar to what is present at room temperature. The experimental approach sheds new insight into the nature of shallow charge traps in these materials and allows identifying molecular systems in which intrinsic transport properties could, in principle, be observed at low temperatures if other transport bottlenecks associated with grain boundaries or contacts could be removed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two new thieno(bis)imide (TBI) based materials, namely NT3N and NT5N are synthesized and analyzed. [•] Their functional properties are compared to those of conventional oligothiophenes. [•] In oFETs, NT3N behaves as n-type semiconductor. [•] NT5N is ambipolar and electroluminescent with electrons mobility up to 0.14cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

Abstract: High mobility bipolar charge carrier transport in organic field-effect transistors (OFETs) can be enabled by a molecular passivation layer and selective electrode materials. Using tetratetracontane as passivation layer bipolar transport was realised in the organic semiconductors copper-phthalocyanine, diindenoperylene, pentacene, TIPS-pentacene and sexithiophene and mobilities of up to 0.1cm2/Vs were achieved for both electrons and holes. Furthermore, the trap and injection behaviour was analysed leading to a more general understanding of the transport levels of the used molecular semiconductors and their limitations for electron and hole transport in OFETs. With this knowledge the transistor operation can be further improved by applying two different electrode materials and a light-emitting transistor was demonstrated. Additionally, the effect of illumination on organic field-effect transistors was investigated for unipolar and bipolar devices. We find that the behaviour of photo-excited electrons and holes depends on the interface between the insulator and the semiconductor and the choice of contact materials. Whereas filling of electron traps by photo-generated charges and the related accumulation field are the reason for changes in charge carrier transport upon illumination without passivation layer, both types of charge carriers can be transported also in unipolar OFETs, if a passivation layer is present. [Copyright &y& Elsevier]

Polyoxometalates (POMs) are a series of molecular metal oxide clusters, which span the two domains of solutes and solid metal oxides. The unique characters of POMs in structure, geometry, and adjustable redox properties have attracted widespread attention in functional material synthesis, catalysis, electronic devices, and electrochemical energy storage and conversion. This review is focused on the links between the intrinsic charge carrier behaviors of POMs from a chemistry-oriented view and their recent ground-breaking developments in related areas. First, the advantageous charge transfer behaviors of POMs in molecular-level electronic devices are summarized. Solar-driven, thermal-driven, and electrochemical-driven charge carrier behaviors of POMs in energy generation, conversion and storage systems are also discussed. Finally, present challenges and fundamental insights are discussed as to the advanced design of functional systems based upon POM building blocks for their possible emerging application areas., (© 2021 Wiley-VCH GmbH.)

Conjugated polymers, e.g., polyacetylene and polythiophenes, conjugated thiophene oligomers and metallophthalocyanines have been proposed in the literature as organic semiconductors for the fabrication of organic-based field-effect transistors, FET. The poor performances generally shown by these FET have been attributed to the very low carrier mobility in organic semiconductors, and the improvement of this parameter has been the objective of a large number of works. The analysis of the mode of operation of organic-based FET, which operate through the formation of an accumulation layer, shows that an ohmic contribution has to be taken into account in the total observed current output of the devices. The conductivity of the organic semiconductor plays thus a significant role in the FET characteristics, although this point has been up to now rarely considered. In this regard, most of the claims in the literature about high mobility achievements are shown to be of limited significance. Conjugated oligomers are actually the only class of organic semiconductors presenting high mobility together with low conductivity, which, furthermore, indicates that interchain transfer of charge may be a much more efficient process than generally believed. [ABSTRACT FROM AUTHOR]

Abstract: The primary quenching in a track of a recoil proton or an alpha particle was studied on the base of “one step” model for molecular crystals of stilbene and doped p-terphenyl as well as for composite scintillators based on the grains of these single crystals. This approach is the first, which takes into account the influence the effect of polarization on recombination of polarons those are generated by ionizing radiation. It was shown that the primary quenching has to be concentration controlled process, which is faster than the track formation along it full length. Results obtained are in good agreement with results of studies of organic crystals as organic semiconductor materials. [Copyright &y& Elsevier]

The design and synthesis of two semiconducting bis (4-ethynyl-bridging 1, 8-naphthalimide) bolaamphiphiles (BENI-COO - and BENI-NH 3 + ) to fabricate supramolecular metal-insulator-semiconductor (MIS) nanostructures for biomimetic hydrogen evolution under visible light irradiation is presented. A H 2 evolution rate of ca. 3.12 mmol g -1 ⋅h -1 and an apparent quantum efficiency (AQE) of ca. 1.63 % at 400 nm were achieved over the BENI-COO - -NH 3 + -Ni MIS photosystem prepared by electrostatic self-assembly of BENI-COO - with the opposite-charged DuBois-Ni catalysts. The hot electrons of photoexcited BENI-COO - nanofibers were tunneled to the molecular Ni collectors across a salt bridge and an alkyl region of 2.2-2.5 nm length at a rate of 6.10×10 8  s -1 , which is five times larger than the BENI-NH 3 + nanoribbons (1.17×10 8  s -1 ). The electric field benefited significantly the electron tunneling dynamics and compensated the charge-separated states insufficient in the BENI-COO - nanofibers., (© 2020 Wiley-VCH GmbH.)

Keywords: 2D; integration; microscale transistors; molecular semiconductors; organic field-effect transistors In article number 1903738, Hongkun Tian, Feng Zhu, and co-workers present fully integrated microscale organic field-effect transistors (micro-OFETs). 2D, integration, microscale transistors, molecular semiconductors, organic field-effect transistors. [Extracted from the article]

Monolithic integration of microscale organic field‐effect transistors (micro‐OFETs) is the only and inevitable path toward low‐cost large‐area electronics and displays. However, to date, such an ultimate technology has not yet evolved due to challenges in positioning and patterning highly crystalline microscale molecular layers as well as in developing micrometer scale integration schemes. In this work, by mastering the local growth of molecular semiconductors on pre‐defined terraces, single‐crystal quasi‐2D molecular layers tens of square micrometers in size are created in dense periodic arrays on a Si substrate. Nondestructive photolithographic processes are developed to pattern micro‐OFETs with mobilities up to 34.6 cm2 V−1 s−1. This work demonstrates the feasibility to integrate arrays of short‐channel micro‐OFETs into electronic circuitry by highly parallel and size scalable fabrication technologies. [ABSTRACT FROM AUTHOR]

The field of spintronics has triggered an enormous revolution in information storage since the first observation of giant magnetoresistance (GMR). Molecular semiconductors are characterized by having very long spin relaxation times up to milliseconds, and are thus widely considered to hold immense potential for spintronic applications. Along with the development of molecular spintronics, it is clear that the study of multipurpose spintronic devices has gradually grown into a new research and development direction. The abundant photoelectric properties of molecular semiconductors and the intriguing functionality of the spinterface, together with novel designs of device structures, have promoted the integration of multiple functions and different mechanisms into discrete spintronic devices. Here, according to the different relationships between the integrated mechanisms, multifunctional molecular spintronic devices containing parallel and interactive types are highlighted. This is followed by the introduction of pure-spin-current-type molecular spintronic devices that have already demonstrated great potential for multifunction exploration. Finally, the challenges and outlook that make this field young and energetic are outlined., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The abundance of solar thermal energy and the widespread demands for waste heat recovery make thermoelectric generators (TEGs) very attractive in harvesting low-cost energy resources. Meanwhile, thermoelectric refrigeration is promising for local cooling and niche applications. In this context there is currently a growing interest in developing organic thermoelectric materials which are flexible, cost-effective, eco-friendly and potentially energy-efficient. In particular, the past several years have witnessed remarkable progress in organic thermoelectric materials and devices. In this review, thermoelectric properties of conducting polymers and small molecules are summarized, with recent progresses in materials, measurements and devices highlighted. Prospects and suggestions for future research efforts are also presented. The organic thermoelectric materials are emerging candidates for green energy conversion., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)