Chanyeol Sehun

http://repository.vnu.edu.vn/handle/VNU_123/28775 With the aim of introduction a new inexpensive co-adsorbent to improve solar cell performance, the influ-ence of nicotinic acid (NTA) used as a co-adsorbent in dye-sensitized solar cells (DSCs) was investigated.  The findings showed that low concentrations of NTA (<10 mM) increased the N719 ruthenium dye loading on the TiO2electrode surface by 10–12%, whereas higher concentrations of NTA lowered the dye loading. The adsorption of NTA onto the TiO2electrode surface was studied by attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, and the blocking effect of NTA toward electron transfer between the electrode and 1,4-dicyanonaphthalene (redox couple electrolyte probe) was investigated by cyclic voltammetry.  Subsequently, the performance of NTA in functional DSCs was evaluated by current–voltage (J–V) DSC characterization and compared with that of DS...

http://repository.vnu.edu.vn/handle/VNU_123/28153 Our research aimed to improve the overall energy conversion efficiency of DSCs by applying nitrogen-doped TiO2 nano-tubes (N-TNT) for the preparation of DSCs photo-anodes. The none-doped TiO2 nano-tubes (TNTs) were synthesized by alkaline hydrothermal treatment of Degussa P25 TiO2 particles in 10M NaOH. The nanotubes were N-doped by reflux in various concentrations of NH4NO3. The effects of nitrogen doping on the structure, morphology, and crystallography of N-TNT were analyzed by transmission electron microscopy (TEM), infrared spectroscopy (IR), Raman spectroscopy, and X-ray photoelectron spectra (XPS). DSCs fabricated with doped N-TNT and TNT was characterized by J-V measurements. Results showed that nitrogen doping significantly enhanced the efficiency of N-TNT cells, reaching the optimum value (η = 7.36%) with 2M nitrogen dopant, compared to η = 4.75% of TNT cells. The high efficiency of the N-TNT cells was attri...