Patent 7276728 was granted and assigned to RICOH COMPANY,LTD. on October, 2007 by the United States Patent and Trademark Office.
A vertical organic transistor comprises a substrate, a first electrode positioned over the substrate, a first semiconductor layer formed over the first electrode, a second electrode formed on the first semiconductor layer and shaped into a prescribed pattern, a second semiconductor layer formed over the second electrode and the first semiconductor layer, and a third electrode formed over the second semiconductor layer. The first semiconductor layer and the second semiconductor layer are made of different semiconductor materials.