CuPc/C60 heterojunction for high responsivity zero bias organic red light photodetector

Abstract

Organic photodetector (OPD), having copper phthalocyanine (CuPc) and fullerene (C60) bilayer heterojunction as an active layer, has been fabricated by employing thermal evaporation method for the red light detection applications. The spectral response has been observed to cover from 300 to 800 nm for the OPD. Experimental results of the OPD reflect good photodiode behavior. Noteworthy, our fabricated OPD has exhibited responsivity of 0.052 A/W and external quantum efficiency (EQE) of 9.28% at wavelength 700 nm and 0 V. Maximum photocurrent density to dark current density ratio has been found to be 4.5 × 104 under the illumination of red light. Detectivity at wavelength 700 nm and 0 V has been found to be on the order of 1011 Jones for the same OPD. Response time and recovery time are found to be 16 and 36 ms, respectively. Our fabricated OPD exhibits excellent stability. Thus, the CuPc/C60 based OPD has been found to be quite promising for the low cost molecular photodetector applications due to its zero bias high responsivity and detectivity.