Electrical characterization of cobalt phthalocyanine/n-Si heterojunction

We report fabrication and characterization of heterojunction diode based on organic semiconductor cobalt phthalocyanine (CoPc) with n-silicon. The electrical characteristics of the CoPc/n-Si junction, along with its photo response, are investigated by current–voltage (I–V) measurements. The morphological properties of the CoPc thin film are investigated using atomic force microscopy (AFM). The I–V characteristics of the junction show rectifying behavior with a rectification ratio of 145 at the bias voltages of ± 3.6 V. The diode parameters such as ideality factor n, barrier height φb and series resistance Rs were determined from the I–V characteristics, which were confirmed by Cheung’s function. The conduction mechanism of the diode is also studied to calculate mobility of the CoPc film. The photo response of the device shows that it can be used as photo-sensor.