FORMATION AND PHOTOLUMINESCENCE PROPERTIES OF POROUS SILICON/COPPER OXIDE NANOCOMPOSITES FABRICATED VIA ELECTROCHEMICAL DEPOSITION TECHNIQUE FOR PHOTODETECTOR APPLICATION

Abstract

Porous silicon (PS)/Copper oxide (CuO) photodetector was fabricated by incorporation of fine CuO nanoparticles synthesized via pulse laser ablation, onto PS substrate using electrochemical deposition technique. The influence of deposition current density (DC) on the structure, microstructure morphology and optical properties were studied using X-Ray diffraction (XRD), Field emission scanning electron microscope (FESEM), and photoluminescence (PL). The microstructure morphology observed using FESEM are strongly dependant on the DC. PL peak spectra was enhanced and getting narrower at high DC 14.2 mA/cm-2 which is candidate to photodetector device application. The diode behavior of the CuO/PS device was prominently superior compared to the PS/Si device. Also, the higher on/off ratio was observed at low bias voltage for the CuO/PS PD. These results attributed to the improved structural quality of the CuO layer deposited on the PS. The flexible three-dimensional structure of the nano-dendrites overcomes the possible lattice mismatch between CuO and Si, leading to low defect densities at the interface. The light trapping nature of the nano-dendrites also contributed to the signal enhancement.