Theory of spin injection into conjugated organic semiconductors

A model to describe electrical spin injection from a ferromagnetic contact into a conjugate organic semiconductor was presented. The model supports the picture that spin-selective tunnelling was critical for the spin polarization injection of charge carrier from a ferromagnetic metal into a semiconductor. It was found that spin density shows strong variation and reversal in sign near the extracting contact. It was also observed that the voltage drop developed across the device for a charge current was different for the case of parallel and antiparallel of the contacts.