Abstract: A low-voltage organic light-emitting device has a light-transmissive hole-injecting electrode on a light-transmissive substrate, and formed over the hole-injecting electrode, in sequence, an organic hole-transporting layer, an organic light-emitting layer, a bi-layer interfacial structure, an electron-transporting layer having an electron affinity higher than an electron affinity of the light-emitting layer, and an electron-injecting electrode. The bi-layer interfacial structure provides effective electron transport from the electron-transporting layer to the light-emitting layer.