Photoelectrical properties of solar sensitive CuO doped carbon photodiodes

Abstract

The CuO doped carbon thin films were produced by using electrochemical deposition and the surface characteristics of the photodiodes were investigated using the scanning electron microscopy and infrared (IR) spectroscopy. Illumination behaviours and current – voltage (I–V) characteristics were assessed. Diodes show rectifying characteristics, where reverse current at backward bias region showed increasing characteristics with increasing illumination intensities. I–V characteristics curves were used to calculate the ideality factor (n) and barrier height (ΦB); the average ideality factor and barrier height were found as 3.74 and 0.51 eV, respectively. Moreover, capacitance – voltage (C–V) and conductance – voltage (G - V) curves were assessed. Capacitance values showed a decreasing trend with increasing frequency. Cadj and Gadj characteristics were evaluated and the density of interface states (Dit) and series resistance (Rs) were calculated using C–V and G - V curves. Detailed investigation of CuO doped amorphous carbon photodiodes (CuO-a:C) revealed that photodiodes exhibited quite good solar sensitive and photoresponsive properties. Overall performance of the photodiodes indicates that CuO-a:C diodes have great potential to be used as a photodetector in optoelectronic devices and their applications.