Ultrasound-assisted electrodeposition of Cu3Se2 nanosheets and efficient solar cell performance

This study is devoted to the synthesis of nanostructured copper selenide (Cu3Se2) thin films through electrodeposition and evaluation of the effect of ultrasonication on the structural, optical, and photovoltaic properties of the deposited films. According to the X-ray (XRD) diffraction patterns, the films are composed of tetragonal Cu3Se2 structures while ultrasonication increases the crystallite sizes and intensifies the diffraction peaks. In addition, ultrasonication increases the lattice parameter and strain of the crystal lattice. Based on the field emission scanning electron microscopy (FESEM) images, the samples electrodeposited in the presence and absence of ultrasound irradiation are both sheet-like while their sheet thicknesses are 66 and 121 nm, respectively. In addition, with respect to the photo-luminescence (PL) spectra of the films, applying ultrasonication increases the intensity of their emission bands and shifts the bands towards lower wavelengths. So that, the absorption spectra exhibit the increase of band gap energy by irradiating ultrasound waves during the synthesis of the nanosheets. The highest value of V-OC, I-SC, and efficiency are obtained 0.47 V, 2.38 mA/cm(2), and 1.11% for the sample synthesized using ultrasonication, respectively. Finally, ultrasound irradiation applies compressive stress on the electrodeposited structures, influences the thickness and morphology of the deposited films and enhances the photovoltaic properties of the solar cells fabricated using the ultrasound-assisted Cu3Se2 layer. (C) 2018 Elsevier B.V. All rights reserved.