Abstract

Spin polarized electron distributions can be generated in nonmagnetic semiconductors optically and by electrical injection from ferromagnetic contacts. Optical spin generation relays on optical selection rules that result from the spin-orbit interaction. Electrical spin injection requires that the semiconductor be driven out of local equilibrium by a spin-polarized current flowing from the ferromagnetic contact. In inorganic semiconductors, such as GaAs, both optical and electrical spin injection have been demonstrated and the transport properties of the spin polarized electron distribution have been probed using Kerr microscopy. The spin-orbit interaction, which enables the optical probes of electron spin distributions in inorganic semiconductors, is often weak in organic semiconductors. I will describe our work on optical and electrical spin injection, and spin transport in inorganic semiconductors; contrast the considerations for spin generation and detection in organic and inorganic semiconductors; and describe our efforts to include metal-organic molecules into conjugated polymer hosts to produce organic semiconductors with a significant spin-orbit interaction.