L. Roza

Multi-cycle growth of boron doped ZnO films as photoanode for Dye-Sensitized Solar Cell (DSSC)

The work is concerned with the fabrication of dye sensitized solar cell (DSSC) utilizing multi-layer boron doped ZnO nanorods films. The B-doped ZnO films were prepared on FTO glass substrate via seed mediated hydrothermal method. Multi-layer B-doped ZnO nanorods were obtained by immersing the sample into a growth solution and repeated the growth process at 90 o C for 30 minutes. The structure of the B-doped ZnO film has been found to exhibit the hexagonal wurtzite structure. The length and diameter of the nanorods increase with the number of the growth cycle. The performance of the DSSC fabricated using the multi-layer B-doped ZnO nanorod was found to be significantly higher than that of the DSSC based on the single layer ZnO nanorod arrays. The best photovoltaic parameters with the JSC of 3.5 mA cm -2 , FF of 0.38 and η of 0.67%, respectively was obtained for the device utilizing the layer with 3 cycles since it possesses the lowest photoluminescence in visible region and lowest Rct.

Morphological, optical, structural and photoelectrochemical properties of TiO2 nanoflower prepared via PVP surfactant assisted liquid phase deposition technique

This paper reports the synthesis of TiO2 nanoflowers as photovoltaic materials of the photoelectrochemical cell (PEC) via the phase liquid deposition technique assisted with a polyvinylpyrrolidone (PVP) surfactant. This work investigates the influence of the surfactant concentration on the morphological, optical, phase structure and PEC properties of the TiO2 PEC cell. The grain size of the TiO2 sample decreases with increase in PVP concentration. The smallest grain size of 16 ± 2 nm is obtained at 8 mM PVP. The thickness of the sample increases with PVP concentration. The concentration of PVP does not influence the optical absorption and band gap of the sample. The phase structure and crystallinity degree of the sample are not influenced by PVP concentration. The crystallite size is around 20 nm. The short-circuit current density, Jsc, of the PEC cell utilising these TiO2 samples increases with decrease in grain size which is due to the increase in PVP concentration. The best Jsc was 0.068 mA cm−2 obtained at 8 mM PVP.