Effect of Copper Content on Structural, Optical and Photovoltaic Characteristics of Manganese Oxide Thin Films Prepared by Pulsed-Laser Deposition Technique

Abstract

In the current study, a 1064nm Nd:YAG laser pulses with pulse duration of 9 ns, energy of 500 mJ and repetition rate of 6 Hz were used to produce Cu-doped MnO thin films. The doping concentration of the thin films was varied (0.03, 0.05, 0.07, and 0.09). The structural, morphological, and optical characteristics of the doped films were investigated. The results showed that the prepared structures are polycrystalline with cubic phase. The surface morphology of the prepared samples suggests the formation of a sponge-like structure that covers all the surface. The grain size increases with increasing Cu concentration. The transmittance is inversely proportional to Cu concentration according to optical measurements. There is a noticeable blue shift in the UV-visible absorption spectra, which causes the optical bandgap to increase as the Cu concentration is increased. The effect of annealing at temperature of 200°C was studied. The Hall effect measurements demonstrate that all produced films exhibit p-type conductivity. Electrical properties of the (MnO)_1-xCu_x/Si heterojunction solar cells were studied and the efficiency was found to decrease as the Cu concentration is increased.