Influence of Mn and Co ions co-doping on the photovoltaic performance of CdS quantum dot sensitized solar cells

The co-precipitation method was used for the synthesis of CdS quantum dots doped with Mn (1%, 2%, and 3%) and Mn (1%)/Co(2%) and Mn(2%)/Co(4%). Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis absorption spectroscopy and photoluminescence (PL) spectroscopy analysis was carried out and evaluated their structural, morphological and optical properties. The quantum dot sensitized solar cell with the incorporation of the samples in photoanode is subjected for J-V characteristics to determine the solar cell parameters. Cubic structure of Mn and Mn/Co co-doped CdS quantum dots was obtained with the grain size of 10 nm confirmed by TEM images. The energy bandgap (E_g) values are varying between 2.98 and 2.89 eV for Mn/CdS and Mn/Co co-doped CdS, which was confirmed from Tauc plot. The maximum power conversion efficiency (1.67%) was obtained for the solar cells Mn (1%) and Co (2%) co-doped CdS with fill factor (ff), open circuit voltage and short circuit current density of 0.67, 0.3703 V and 6.7365 mA/cm², respectively.