By means of ab initio calculations and spin-polarized scanning tunneling microscopy experiments the creation of a complex energy dependent magnetic structure with a tailored spin-polarized interface is demonstrated. We show this novel effect by adsorbing organic molecules containing $\ensuremath{\pi}({p}_{z})$ electrons onto a magnetic surface. The hybridization of the out-of-plane ${p}_{z}$ atomic-type orbitals with the $d$ states of the metal leads to the inversion of the spin polarization at the organic site due to a ${p}_{z}\mathrm{\text{\ensuremath{-}}}d$ Zener exchange-type mechanism. As a key result, we demonstrate the possibility to selectively and efficiently inject spin-up and spin-down electrons from a ferromagnetic-organic interface, an effect which can be exploited in future spintronic devices.

Design of the Local Spin Polarization at the Organic-Ferromagnetic Interface

The effective separation of photogenerated carriers plays a vital role in photocatalytic reactions. In addition to the intrinsic driving force of photocatalysis, an external field generating an enh...

Recent Advances in Noncontact External-Field-Assisted Photocatalysis: From Fundamentals to Applications

Spin-crossover (SCO) active transition metal complexes are an important class of switchable molecular materials due to their bistable spin-state switching characteristics at or around room temperature. Vacuum-sublimable SCO complexes are a subclass of SCO complexes suitable for fabricating ultraclean spin-switchable films desirable for applications, especially in molecular electronics/spintronics. Consequently, on-surface SCO of thin-films of sublimable SCO complexes have been studied employing spectroscopy and microscopy techniques, and results of fundamental and technological importance have been obtained. This Review provides complete coverage of advances made in the field of vacuum-sublimable SCO complexes: progress made in the design and synthesis of sublimable functional SCO complexes, on-surface SCO of molecular and multilayer thick films, and various molecular and thin-film device architectures based on the sublimable SCO complexes.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.201911256

Sublimable Spin-Crossover Complexes: From Spin-State Switching to Molecular Devices.

Organic semiconductors and organic-inorganic hybrids are promising materials for spintronic-based memory devices. Recently, an alternative route to organic spintronic based on chiral-induced spin selectivity (CISS) is suggested. In the CISS effect, the chirality of the molecular system itself acts as a spin filter, thus avoiding the use of magnets for spin injection. Here, spin filtering in excess of 85% in helical π-conjugated materials based on supramolecular nanofibers at room temperature is reported. The high spin-filtering efficiency can even be observed in nanofibers assembled from mixtures of chiral and achiral molecules through chiral amplification effect. Furthermore and most excitingly, it is shown that both "up" and "down" orientations of filtered spins can be obtained in a single enantiopure system via the temperature-dependent helicity (P and M) inversion of supramolecular nanofibers. The findings showcase that materials based on helical noncovalently assembled systems are modular platforms with an emerging structure-property relationship for spintronic applications.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201904965

Highly Efficient and Tunable Filtering of Electrons' Spin by Supramolecular Chirality of Nanofiber-Based Materials.

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.

Recent Advances in Molecular Spintronics: Multifunctional Spintronic Devices.

Because of the considerable advantages of functional molecules as well as supramolecules, such as the low cost, light weight, flexibility, and large area preparation via the solution method, molecular electronics has grown into an active and rapidly developing research field over the past few decades. Beyond those well-known advantages, a very long spin relaxation time of π-conjugated molecules, due to the weak spin-orbit coupling, facilitates a pioneering but fast-growing research field, known as molecular spintronics. Recently, a series of sustained progresses have been achieved with various π-conjugated molecular matrixes where spin transport is undoubtedly an important point for the spin physical process and multifunctional applications. Currently, most studies on spin transport are carried out with a molecule-based spin valve, which shows a typical geometry with a thin-film molecular layer sandwiched between two ferromagnetic electrodes. In such a device, the spin transport process has been demonstrated to have a close correlation with spin relaxation time and charge carrier mobility of π-conjugated molecules. In this review, the recent advances of spin transport in these two aspects have been systematically summarized. Particularly, spin transport in π-conjugated molecular materials, considered as promising for spintronics development, have also been highlighted, including molecular single crystal, cocrystal, solid solution as well as other highly ordered supramolecular structures.

/pdf/spin-transport-in-organic-molecules-38kssfb9cm.pdf

Spin Transport in Organic Molecules.

18.4% efficiency achieved by the cathode interface engineering in non-fullerene polymer solar cells

π-Conjugated semiconductors, primarily composed of elements with low atomic number, are regarded as promising spin-transport materials due to the weak spin-orbit coupling interaction and hence long spin relaxation time. Moreover, a large number of additional functions of organic semiconductors (OSCs), such as the abundant photo-electric properties, flexibility, and tailorability, endow the organic spintronic devices more unique properties and functionalities. Particularly, the integration of the photo-electric functionality and excellent spin transport property of OSCs in a single spintronic device has even shown great potential for the realization of spin manipulation in OSCs. In this review, the application of OSCs in spintronic study will be succinctly discussed. As the most important and extensive application, the long-distance spin transport property of OSCs will be discussed first. Subsequently, several multifunctional spintronic devices based on OSCs will be summarized. After that, the organic-based magnets used for the electrodes of spintronic devices will be introduced. Finally, according to the latest progress, spin manipulation in OSCs via novel spintronic devices together with other prospects and challenges will be outlined.

/pdf/the-application-of-organic-semiconductor-materials-in-1dc8w587jm.pdf

The Application of Organic Semiconductor Materials in Spintronics.

https://iopscience.iop.org/article/10.1088/1674-1056/27/10/107202/pdf

Lidan Guo

Papers

Recent Advances in Molecular Spintronics: Multifunctional Spintronic Devices.

Spin Transport in Organic Molecules.

18.4% efficiency achieved by the cathode interface engineering in non-fullerene polymer solar cells

The Application of Organic Semiconductor Materials in Spintronics.

Recent spinterfacial studies targeted to spin manipulation in molecular spintronic devices