TUNING THE STRUCTURAL, OPTICAL AND PHOTOVOLTAIC CHARACTERISTICS OF FABRICATED N-TIO\(_2\)/P-CUO AND N-TIO\(_2\)/P-CU\(_2\)O SOLAR CELLS BY CHANGING THE BACK CONTACT ELECTRODES

The current work focuses on working a comparison between two solar cells made with the combination, n-TiO2/p-CuO, and n-TiO2/p-Cu2O devices. The structural, optical, and photovoltaic characteristics were detailed. In the optical section, the optical measurements for the TiO2 (120 nm), CuO (200 nm), and Cu2O (200 nm) thin films were illustrated, and then the energy of optical transition was calculated based on the Tauc formula for each layer. The direct optical gap energies of TiO2, CuO, and Cu2O thin films are 3.24, 1.77, and 2.18 eV, respectively. The front contact electrode in both systems is an ITO- coated glass layer, while the back contact electrodes are Pt, Ni, Au, Co, Ag, Cu, Al, and Mo. The effect of various metals as back contact electrodes on the photovoltaic characteristics of fabricated devices was investigated. The optical and structural characteristics showed the superiority of the fabricated device n-TiO2/p-CuO over the fabricated device n-TiO2/p-Cu2O.