An electro-optically active organic diode, for example an organic light emitting diode (OLED), comprises an anode electrode (102), a cathode electrode (122) and an electro-optically active organic layer (110) arranged in-between. A cover layer (124) is arranged in contact with a surface of the cathode layer (122) so that the cathode layer (122) is positioned between the organic layer (110) and the cover layer (124), which is formed of a substantially inert material with respect to a cathode layer (122) material in contact with said cover layer (124). The inert material is deposited on said surface of the cathode layer (122) so that the complete surface is covered and surface defects eliminated. A short protection layer (120) is further arranged between said cathode electrode (122) and said electro-optically active organic layer (110), and adjacent to said cathode electrode (122), and is formed of an inorganic semiconductor material. The cover layer (124) and the short protection layer (120) together reduce the risk of shorts to occur between the cathode (122) and the anode (102) and thus increase reliability of the electro-optically active organic diode.