N-DOPED TiO2/CdS NANOCOMPOSITE FILMS: SILAR SYNTHESIS, CHARACTERIZATION AND APPLICATION IN QUANTUM DOTS SOLAR CELL

The N-doped TiO2/CdS nanocomposite films have been prepared through a successive ionic layer adsorption and reaction (SILAR) method on the N-doped TiO2 thin films with cadmium nitrate as Cd source and sodium sulphide as S... [ view full abstract ]

The N-doped TiO₂/CdS nanocomposite films have been prepared through a successive ionic layer adsorption and reaction (SILAR) method on the N-doped TiO₂ thin films with cadmium nitrate as Cd source and sodium sulphide as S precursor. The SILAR cycle was varied to study the CdS layer formation and its influence to the properties of resulted nanocomposite, i.e. 1, 5, 10, 20, and 50 cycles, respectively. The resulting materials were characterized using X-Ray Diffraction (XRD), UV/Vis Spectroscopy, FTIR Spectrophotometer, and Scanning Electron Microscopy (SEM). The result showed that the higher SILAR cycle resulted in a smaller CdS crystallite size and a higher band gap energy. The higher SILAR cycle was also provided the more intense response in visible light area. The prepared N-doped TiO₂/CdS nanocomposite films were then applied in the quantum dots-sensitized solar cells (QDSSC) system. The solar cell performa test showed that there is an optimum cycle which results in a highest power conversion. The quantum dot solar cells based on N-doped TiO₂/CdS nanocomposite prepared with 20 cycles provided the highest performa with overall efficiency of 8.3%.  Thus, by varying the cycle number in the SILAR synthesis process, it is easy for tuning the nanocomposite properties that fulfill the requirements as sensitized-semiconductor material in the solar cell system.

Keywords : nanocomposite, SILAR method, quantum dots, N-doped TiO₂, CdS, QDSSC