The effect of rear earth doping CdS nanostructure on structural, optical and photoconductivity properties

Abstract

Rare earth elements (Cerium, Lanthanum and Neodymium) doped CdS thin films are prepared using the chemical Spray Pyrolysis Method with temperature 200 oC. The X-ray diffraction (XRD) analysis refers that pure CdS and CdS:Ce, CdS:La and CdS:Nd thin films showed the hexagonal crystalline phase. The crystallite size determined by the Debye-Scherrer equation and the range was (35.8– 23.76 nm), and it was confirmed by field emission scanning electron microscopy (FE-SEM). The pure and doped CdS shows a direct band gap (2.57 to 2.72 eV), which was obtained by transmittance. The room-temperature photoluminescence of pure and doped CdS shows large peak at 431 nm, and two small peaks at (530 and 610 nm). The Current – voltage measurement in dark and illumination (100 mW/cm2, 183 mW/cm2 and 288 mW/cm2) condition. The photocurrent increases and the resistivity decreases with the light intensity increases. So film reveals photoconductivity phenomena suggesting it's useful for optoelectronic applications.