Study of spin transport in polyfluorene films

Haoliang Liu; Matthew Groesbeck; Evan Lafalce; Xiaojie Liu; Zeev Valy Vardeny

doi:10.1117/1.JPE.8.032212

8 May 2018 Study of spin transport in polyfluorene films

Haoliang Liu, Matthew Groesbeck, Evan Lafalce, Xiaojie Liu, Zeev Valy Vardeny

Author Affiliations +

Journal of Photonics for Energy, Vol. 8, Issue 3, 032212 (May 2018). https://doi.org/10.1117/1.JPE.8.032212

Abstract

We have investigated spin transport in films of polyfluorene, a π-conjugated polymer, using the technique of “spin pumping” from a ferromagnet substrate, namely Ni₈₀Fe₂₀ in a NiFe/polyfluorene/Pt trilayer device at room temperature. Pure spin current (without carrier injection) is generated in the polymer film by microwave excitation of the NiFe magnetic moment at ferromagnetic resonance conditions. The induced spin current through the ferromagnet/polymer interface crosses the polymer layer and is detected by a Pt overlayer in the device, where it is converted into electric current via the inverse spin Hall effect. We have successfully determined the spin diffusion length, λ_S, in the polyfluorene film by varying the polymer thickness in the trilayer structure, and found λ_S = 118 ± 9 nm. We also measured the charge-carrier mobility, μ in polyfluorene film using the time-of-flight technique and found it to be affected by dispersive transport. From the obtained λ_S and μ values, we estimated the spin relaxation time in polyfluorene to be ∼5 μs at room temperature.

Citation Download Citation

Haoliang Liu, Matthew Groesbeck, Evan Lafalce, Xiaojie Liu, and Zeev Valy Vardeny "Study of spin transport in polyfluorene films," Journal of Photonics for Energy 8(3), 032212 (8 May 2018). https://doi.org/10.1117/1.JPE.8.032212

Received: 7 February 2018; Accepted: 19 April 2018; Published: 8 May 2018

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available