Quasi-surface emission in vertical organic lightemitting transistors with network electrode

We demonstrate a vertical-type organic light-emitting transistor(VOLET) with a network electrode of closed topology for quasi-surfaceemission. In our VOLET, the spatial distribution of the surface emissiondepends primarily on the relative scale of the aperture in the networkelectrode to the characteristic length for the charge carrier recombination.Due to the closed topology in the network of the source electrode, thecharge transport and the resultant carrier recombination are substantiallyextended from individual network boundaries toward the correspondingaperture centers in the source electrode. The luminance was found to bewell-controlled by the gate voltage through an organic semiconductinglayer over the network source electrode.