The Application of Organic Semiconductor Materials in Spintronics

Abstract

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.

Molecular Functionalization and Emergence of Long-Range Spin-Dependent Phenomena in Two-Dimensional Carbon Nanotube Networks

“…Intersections of two apparently disparate areas of organic chemistry, carbon nanotubes (CNTs) and spintronics, have intrigued the scientific community for several decades. Organic molecular functionalization of CNTs is a common technique for various nanotechnology applications. − Spin transport in CNTs has been explored extensively due to its potential application in future information technology. , The area of “organic spintronics” (or “molecular spintronics”) explores spin transport in organic molecular systems and has found surprisingly long spin lifetimes which could be useful for quantum information processing and other applications . Recent developments in this area have unraveled an intriguing connection between organic molecular chirality and carrier spin polarization, often dubbed as “chirality-induced spin selectivity” or CISS. − The key observations are that the transmission of spin-unpolarized electrons through chiral molecules can polarize the carrier spins via a spin-filtering effect and that the spin orientation is determined by molecular chirality (left or right handed) .…”

“…7,8 The area of "organic spintronics" (or "molecular spintronics") explores spin transport in organic molecular systems and has found surprisingly long spin lifetimes which could be useful for quantum information processing and other applications. 9 Recent developments in this area have unraveled an intriguing connection between organic molecular chirality and carrier spin polarization, often dubbed as "chiralityinduced spin selectivity" or CISS. 10−12 The key observations are that the transmission of spin-unpolarized electrons through chiral molecules can polarize the carrier spins via a spinfiltering effect and that the spin orientation is determined by molecular chirality (left or right handed).…”

Molecular spinterface in F4TCNQ-doped polymer spin valves

“…[13][14][15][16][17] The organic semiconductor materials adopted in OSVs mainly include small molecules and polymers. [18][19][20] As for the spin transport in p-conjugated polymers, their spin diffusion length (l s ) will be limited by the relatively low mobility (m) of the localized polarons which is governed by the thermally activated hopping mechanism, considering the relationship of l s ¼ ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi mk B Tt=e p . 21,22 Moreover, the large resistivity of the organic intermediate layer is also a bottleneck for spin injection from most FM electrodes due to the famous conductivity mismatch problem.…”

Structural, Electrical and Optical Properties of Pyrrolo[1,2-i][1,7] Phenanthroline-Based Organic Semiconductors

“…Continuing our research focused on the synthesis and characterization of new fused N-heterocyclic functional compounds [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], we present in this paper the investigation of microstructural, electrical and optical properties of a series of pyrrolo[1,2- i ][1,7] phenanthroline derivatives LL(1–3), in the form of thin films.…”