Electrical and photocurrent characteristics of Au/PVA (Co-doped)/n-Si photoconductive diodes

In this work, we investigate the some main electrical and photocurrent properties of the Au/PVA(Co-doped)/n-Si diodes by using current–voltage (I–V) measurements at dark and various illumination intensity. Two types of diodes with and without polyvinyl alcohol (PVA) (Co-doped) polymeric interfacial layer were fabricated and measured at room temperature. Results show that the polymeric interfacial layers and series resistance (Rs) strongly affect the main electrical parameters of these structures. Also, metal/polymer/semiconductor (MPS) diode with PVA (Co-doped) interfacial organic layer is very sensitive to the light such that the current in reverse bias region increase by 103–104 times with the increasing illumination intensity. The open circuit voltage Voc and short-circuit current Isc values of this MPS diode under 100 mW/cm2 illumination intensity were found as 0.28 V and 19.3 μA, respectively.

► The photocurrent properties of MS and MPS SBDs were investigated and compared. ► Voc and Isc values of MPS under 100 mW/cm2 are 0.28 V and 19.3 μA, respectively. ► The NSS values are lower than those obtained without considering the Rs. ► The existence of polymeric layer decreased the leakage current. ► MPS structure with Co-doped PVA layer is suitable for opto-electronic applications.