Abstract: A photocoupler comprising a light emitting device and a light detecting device both of which are made of amorphous semiconductors. The light emitting device is an amorphous semiconductor thin film light emitting diode which emits light when stimulated by an electric stimuli. The light detecting device is either an amorphous semiconductor thin film solar cell which produces an electric signal when exposed to light or a photoconductive type amorphous semiconductor thin film whose electrical conductivity varies when exposed to light. Both of these light detecting devices thus give an indication of detected light. These types of photocouplers have low production costs, can be manufactured in different sizes are relatively easy to mass produce and are compact as well as light weight.

Abstract: An amorphous semiconductor thin film light emitting diode comprising of a first electrode metal sheet substrate, amorphous semiconductor layers and a second optically transparent electrode. The first electrode metal sheet substrate acts as the support of the electrode and provides ruggedness, good thermal stability and dissipation of heat, good reflectance and flexibility. The device may further include electrically insulating layers which cause a pattern of light to be emitted by the diode, by controlling the passage of current through areas of the amorphous semiconductor layers.