OPTOCOUPLER MADE FROM SEMICONDUCTING POLYMERS

Optocouplers (optoisolators) were fabricated using semiconducting polymers. The input unit is a polymer light emitting diode with an external quantum efficiency of approximately 1% photons/electron. The output unit is a polymer photodiode with a quantum yield of approximately 35% electrons/photon at 590 nm. Both units can be operated at bias voltages sufficiently low to be compatible with TTL and complementary metal-oxide semiconductor logic circuits. Since the transfer characteristic is nearly linear, the polymer optocoupler can be used in analogue circuits as well. The current transfer ratio reaches 2 x 10(-3) under-10V reverse bias, comparable to that of commercial inorganic optocouplers.