Electro-optical characteristics were studied on the organic semiconductor materials exhibiting molecular alignment based on molecular self-organization in their liquid crystal phases. It was confirmed that these organic semiconductor materials exhibit very fast electron transport in the smectic mesophases as well as hole transport, both of which were independent on electric field and temperature. Above all, the ambipolar carrier transport in these materials make it possible to fabricate a simple electroluminescence cell without a layered structure required in conventional organic electroluminescence cells. In this paper, we fabricated electroluminescence cell with surface type of molybdenum or aluminum electrodes using hexyldodecylterthiophene (6-TTP-12) as a light emitting semiconducting material. The electroluminescence cell shows a green light emission when a dc bias is applied to the electrode. It was revealed that the light emission took place in the vicinity of the cathode interface, indicating that the hole is the majority carrier in the cell when the molybdenum or aluminum electrodes were applied. In addition, the light emission luminance of the cell is controllable in the external electrode which formed under insulating film as a gate electrode.