The present invention discloses an organic light-emitting diode (LED). The organic light emitting diode is supported on an indium/tin oxide 110 (ITO) coated glass substrate 105. The organic light-emitting diode includes an amorphous-silicon (.alpha.-Si) resistive layer 115 covering the ITO 110 coated glass substrate 105. The organic light-emitting diode 100 further includes a polyaniline (PANI) layer 120 covering the amorphous silicon (.alpha.-Si) resistive layer 115 and an organic light emitting layer 125 overlying the PANI layer 120. And, the organic light-emitting diode 100 further has a conductive electrode layer 130 covering the light emitting layer 125. In a preferred embodiment, the amorphous silicon (.alpha.-Si) resistive layer 115 functioning as a current limiting layer for limiting a current density conducted between the ITO 110 coated glass substrate 105 and the conductive electrode layer 130 under a maximum allowable current density of 1000 mA/cm.sup.2. In another preferred embodiment, the amorphous silicon (.alpha.-Si) resistive layer 115 functioning as a current distribution layer for distributing a current conducted between the ITO coated glass substrate and the conductive electrode layer. Thus, the difference between a greatest current density from a smallest current density is under a maximum allowable current density difference of 1000 mA/cm.sup.2. In summary, this invention discloses an organic light-emitting diode (LED) 100 that includes an inorganic layer 115 functioning as a current limiting layer.
Regio-regular polythiophenes used in diodes which are not light emitting or photovoltaic. High quality, processable thin film polymer films can be made. The thin film can have a thickness of about 50 nm to about one micron, and the conductive thin film can be applied by spin casting, drop casting, screening, ink-jetting, transfer or roll coating. The polythiophenes can be homopolymers or copolymers. The regio-regular poly(3-substitutedthiophene) can be derivatized so that the 3-substituent is an alkyl, aryl, or alkyl/aryl moiety with a heteroatom substitution in either the .alpha.- or beta-position of the 3-substituent.
An organic semiconductor device with a vertical structure having both functions of an organic thin film transistor and light-emitting element, where the electrical characteristics as both the organic thin film transistor and light-emitting element can be controlled in the case of forming a gate electrode with an organic conductive film, and a manufacturing method thereof. The above organic semiconductor device has such a structure that organic semiconductor films are sandwiched between a pair of electrodes functioning as a source electrode and drain electrode of an organic thin film transistor and also functioning as an anode and cathode of a light-emitting element, a thin organic conductive film functioning as a gate electrode is sandwiched between the organic semiconductor films, and a part of the organic conductive film is electrically connected to an auxiliary electrode, thereby the electrical characteristics as both the organic thin film transistor and light-emitting element can be controlled.