Effect of Electric-Field on Spin Injection Efficiency in the Organic Semiconductors

Abstract:

The spin injection efficiency in the ferromagnet/ organic semiconductors system (FM/OSE) was studied under an external electric-field. It is found that the spin injection efficiency can be strongly influenced by the spin-dependent electrical conductivity and the downstream spin diffusion length of polarons. With the increase of external electric-field, the downstream spin diffusion length increases and makes the spin-dependent electrical conductivity increase, too. So the spin injection efficiency is enhanced. When the external electric-field increases from 1 to 10 mV/μm at T=80K, the spin injection efficiency increases about 20%. It seems that the downstream spin diffusion length is an significant factor to affect the spin injection efficiency in the FM/ OSE under an external electric-field.

• Periodical: Materials Science Forum (Volume 852)
• Pages: 704-707
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.852.704
• Online since: April 2016
• Authors: Yi Lin Mi, Jiang Nan Gao
• Keywords: Spin Injection Effiency, Spin Polarization, Spin-Dependent Electrical Conductivity

References

[1] Z. H. Xiong, D. Wu, Z. V. Vardeny and J. Shi: Giant Magnetoresistance in Organic Spin-valves, Nature. , 2004, 427(6977), 821-824.

DOI: 10.1038/nature02325

[2] Y. L. Mi, M. Zhang, H. Yan: Effect of Different Conductivity between the Spin Polarons on Spin Injection in a Ferromagnet/ Organic Semiconductor System, Phys. Lett. A. , 2008, 372 (20), 3734-3737.

DOI: 10.1016/j.physleta.2008.02.036

[3] Y. L. Mi, M. Zhang, H. Yan: Effect of Electric-field on Spin Transport and Spin Current in an Organic Semiconductor System, Phys. Lett. A. , 2008, 372 (42), 6434-6437.

DOI: 10.1016/j.physleta.2008.08.040

[4] S. Majumdar, R. Laiho, P. Laukkanen, I. J. Väyrynen, H. S. Majumdar and R. Österbacka: Application of Regioregular Polythiophene in Spintronic Devices: Effect of Interface, Appl. Phys. Lett. , 2006, 89 (12), 122114-1-122114-3.

DOI: 10.1063/1.2356463

[5] V. Dediu, M. Murgia, F. C. Matacotta, C. Taliani and S. Barbanera: Room Temperature Spin Polarized Injection in Organic Semiconductor, Solid State Commun. , 2002, 122(3-4), 181-184.

DOI: 10.1016/s0038-1098(02)00090-x

[6] J. F. Ren, J. Y. Fu, D. S. Liu, L. M. Mei and S. J. Xie: Diffusion Theory of Spin Injection into Organic Polymers, J. Phys.: Condens. Matter. , 2005, 17(15), 2341-2347.

DOI: 10.1088/0953-8984/17/15/007

[7] J. F. Ren, J .Y. Fu, D. S. Liu, L. M. Mei and S. J. Xie: Spin-polarized Current in a Ferromagnetic/ Organic System, J. Appl. Phys. , 2005, 98 (7), 074503-1-074503-15.

DOI: 10.1063/1.2076448

[8] Z. G. Yu and M. E. Flatte: Electric-field Dependent Spin Diffusion and Spin Injection into Semiconductors, Phys. Rew. B, 2002, 63 (20), 201202-1-201201-4.

DOI: 10.1109/intmag.2003.1230275

[9] Z. G. Yu and M. E. Flatte: Spin Diffusion and Injection in Semiconductor Structures: Electric Field Effects, Phys. Rew. B, 2002, 66 (23), 235302-1-235302-14.

[10] M. Idrish Miah, E. MacA. Gray: Spin Transport and Spin Current Detection in Semiconductors, Solid State Sciences. , 2008, 10 (2) Vol., 205-210.

DOI: 10.1016/j.solidstatesciences.2007.07.038

[11] M. Idrish Miah: Drift-diffusion Crossover and the Intrinsic Spin Diffusion Lengths in Semiconductors, J. Appl. Phys. , 2008, 103 (6), 063718-1-063718-4.

DOI: 10.1063/1.3624614

[12] I. Martin: Spin-drift Transport and its Applications, Phys. Rev. B. , 2003, 67 (1), 014421-1-014421-5.

[13] Y. V. Pershin and V. Privman: Focusing of Spin Polarization in Semiconductors by Inhomogeneous Doping, Phys. Rev. Lett. , 2003, 90 (25), 256602-1-256602-4.

DOI: 10.1103/physrevlett.90.256602

[14] Y. V. Pershin: Accumulation of Electron Spin Polarization at Semiconductor Interfaces, Phys. Rev. B., 2003, 68 (23), 233309-1-233309-4.

DOI: 10.1103/physrevb.68.233309

[15] Y. V. Pershin: Drift–diffusion approach to spin-polarized transport, Physica E. , 2004, 23 (1-2), 226-231.

DOI: 10.1016/j.physe.2004.03.007