We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Engineering of Spin Injection and Spin Transport in Organic Spin Valves Using π-Conjugated Polymer Brushes.
- Authors
Geng, Rugang; Roy, Anandi; Zhao, Wenbo; Subedi, Ram Chandra; Li, Xiaoguang; Locklin, Jason; Nguyen, Tho Duc
- Abstract
Charge transport in amorphous organic semiconductors is governed by carriers hopping between localized states with small spin diffusion length. Furthermore, the interfacial resistance of organic spin valves (OSVs) is poorly controlled resulting in controversial reports of the magnetoresistance (MR) response. Here, surface-initiated Kumada transfer polycondensation is used to covalently graft π-conjugated poly(3-methylthiophene) brushes from the La0.67Sr0.33MnO3 (LSMO) bottom electrode. The covalent attachment along with the brush morphology allows control over the LSMO/brush interfacial resistance and large spacer mobility. Remarkably, with 15 nm brush spacer layer, an optimum MR effect of 70% at cryogenic temperatures and a MR of 2.7% at 280 K are observed. The temperature dependence of the MR is nearly an order of magnitude weaker than that found in control OSVs made from spin-coated poly(3-hexylthiophene). Using a variety of different brush layer thicknesses, the thickness-dependent MR at 20 K is investigated. A spin diffusion length of 17 nm at −5 mV junction voltage rapidly increased to 48.4 nm at −260 mV.
- Subjects
SEMICONDUCTOR research; NUCLEAR spin; MAGNETORESISTANCE; CRYOGENICS; INTERFACIAL resistance
- Publication
Advanced Functional Materials, 2016, Vol 26, Issue 22, p3999
- ISSN
1616-301X
- Publication type
Article
- DOI
10.1002/adfm.201504201