Semitransparent organic photodetectors utilizing sputter-deposited indium tin oxide for top contact electrode

Semitransparent organic photodetectors with the heterostructure of copper phthalocyanine (CuPc) and N,N'-bis(2,5-di-tert-butylphenyl) 3,4,9,10-perylenedicarboximide (BPPC) were fabricated using sputter-deposited indium tin oxide (ITO) for a top contact electrode, and the I-V and frequency characteristics were investigated. To prevent ITO penetration into an organic layer, an amorphous carbon nitride (a-C:N) buffer layer was placed between the organic layer and an ITO electrode. A cutoff frequency of more than 2 MHz was obtained for a semitransparent photodetector by applying a reverse bias voltage of -2V under visible light illumination. We demonstrated that the fabricated semitransparent organic photodetectors can be applicable to a photoreflector with light-emitting diodes for integrated devices with organic light-emitting devices.