A bottom-emitting organic light-emitting diode (OLED) device, comprising: a transparent substrate; an optical isolation cavity formed over the substrate having a refractive index lower than the refractive index of the substrate; a transparent electrode formed over the optical isolation cavity; one or more layers of organic light-emitting material formed over the transparent electrode; a second electrode formed over the one or more layers of organic light-emitting material; and a light-scattering layer formed over the optical isolation cavity; wherein the transparent electrode or a second layer formed between the optical isolation cavity and the transparent electrode comprises one or more openings leading to the optical isolation cavity, and the cavity is formed by etching a sacrificial layer deposited between the substrate and the transparent electrode or the second layer through the one or more openings.