Influence of intensity on copper phthalocyanine based organic phototransistors

Abstract

High performance photosensing devices have been effectively produced utilizing copper phthalocyanine (CuPc) as an organic photoactive material. The opto-electrical effects of organic semiconductor (OSC) based phototransistors are concentrated in this work. The light affectability of the thin film is examined using UV–Visible spectrometer. The current–voltage (I-V) curves with and without illumination represent that the device is highly sensitive towards illumination. The effect of illumination on the opto-electrical properties of the devices has been also investigated with constant bias voltage. The mobility of the fabricated devices could be enlarged definitely after light illumination. The fabricated device shows p-channel working with greatest carrier mobility of 0.41 ± 0.02 cm2/Vs under illumination. It was found that enhanced responsivity and an improved detectivity could be accomplished in lower intensity. The maximum responsivity and detectivity obtained from these devices were 1.14 ± 0 0.01 A/W and 4.57 ± 0.02 × 1011 Jones with 5 mW/cm2 intensity at very small bias voltage. Both high responsivity and detectivity portrayed in this study firmly suggest that CuPc based phototransistors are a good candidate for upcoming photosensitive and optoelectronic device applications.