Organic magnetoresistance from deep traps

Abstract

We predict that singly-occupied carrier traps, produced by electrical stress or irradiation within organic semiconductors, can cause spin blockades and the large room-temperature magnetoresistance known as organic magnetoresistance. The blockade occurs because many singly-occupied traps can only become doubly occupied in a spin-singlet configuration. Magnetic-field effects on spin mixing during transport dramatically modify the effects of this blockade and produce magnetoresistance.We calculate the quantitative effects of these traps on organic magnetoresistance from percolation theory and find a dramatic nonlinear dependence of the saturated magnetoresistance on trap density, leading to values $\sim$ 20%, within the theory's range of validity.

arXiv comment4 pages, 3 figures. Accepted into Journal of Applied Physics

References in corpus (5)

• Large magnetoresistance in $\pi$-conjugated semiconductor thin film devices
• Large magnetoresistance at room-temperature in semiconducting polymer sandwich devices
• Spin-flip induced magnetoresistance in positionally disordered organic solids
• The effects of spin-spin interactions on magnetoresistance in disordered organic semiconductors
• Tunnel magnetoresistance in organic spin valves in the regime of multi-step tunneling

Cited by in corpus (4)

• Immense magnetic response of exciplex light emission due to correlated spin-charge dynamics
• Extraction of Isotropic Electron-Nuclear Hyperfine Coupling Constants of Paramagnetic Point Defects from Near-Zero Field Magnetoresistance Spectra via Least Squares Fitting to Models Developed from the Stochastic Quantum Liouville Equation
• Anomalous organic magnetoresistance from competing carrier-spin-dependent interactions with localized electronic and nuclear spins
• Spin transport with traps: dramatic narrowing of the Hanle curve