ON THE COVER
Organic single crystals. This issue of MRS Bulletin provides an overview of the state of the art of the field of organic semiconductor single crystals, including materials, devices, and theories. The cover shows a single crystal of rubrene-the highest mobility organic semiconductor frequently used in experiments and modeling. Studies on rubrene reveal fundamental charge transport and optical properties of highly ordered molecular materials relevant to organic electronics and photonics. The photograph is courtesy of Pavel Irkhin, Rutgers University. See the technical theme that begins on page 15.