An OLED(Organic Light Emitting Diode) and a plurality of organic light emitting diodes are provided to allow high roughness of a metal substrate, a conductive layer or an insulating layer by using doped charge carrier transport layers. An OLED has a layer arrangement. The layer arrangement includes an electrode, a counter electrode, an organic layer sequence. The organic layer sequence is arranged between the electrode and the counter electrode. The organic layer sequence is arranged on the metal substrate and one or more organic transport layers. Each organic transmission layer includes the mixture for increasing the electrical conductivity. The organic layer sequence has at least one of the charge carrier transport property and the charge carrier injection property. The layer coated on the metal substrate is made of varnish or polymer material. The layer coated on the metal substrate smooths the surface of the metal substrate.