Three-dimensional organic field-effect transistors: Charge accumulation in the vertical semiconductor channels

A three-dimensional organic field-effect transistor is developed to accumulate charge in its vertical semiconductor channel so that space availability for the field-induced carriers is essentially multiplied. A multicolumnar structure is built incorporating a vertical layer of soluble benzothieno-benzothiophene derivative. Pronounced field-effect performance is realized with the well-defined saturation in the output, where extremely large value of channel width divided by length enables current amplification up to similar to 2 mu A in a square pixel even with relatively low carrier mobility of 10(-4) cm(2) /V s. The result demonstrates usefulness of the three-dimensional structure in achieving sufficient current for matrix-controlling devices in flat-panel displays. c 2008 American Institute of Physics. [DOI: 10.1063/1.3007984]