Risa Suryana

Beta-Carotene Dye of Daucus carota as Sensitizer on Dye-Sensitized Solar Cell

Beta-carotene dye which is extracted from daucus carota material was used as sensitizer to fabricate dye-sensitized solar cell (DSSC). DSSCs were arranged in a sandwich structure consisting of fluorine-doped tin oxide (FTO) as a transparent conducting oxide (TCO), titanium dioxide (TiO2) layer, beta-carotene dye, iodide/tri-iodide redox electrolyte, and carbon layer as a counter electrode. Beta-carotene dye has an absorbance in wavelength zones from 415 to 508 nm. Meanwhile, it has the largest photoconductivity of 28.3×10-4 and 8.2×10-4 (Ω.m)-1 in dark and bright conditions, respectively. Moreover, the photoelectrochemical performance of the DSSC based on beta-carotene dye showed that the maximum voltage of 23.9×10-2 V and the maximum current of 3.3×10-5 A. However, the photo-to-electric conversion efficiency of this DSSC was very low i.e. 12.5×10-4 %.

Influence of Mass Ratio of Aquadest and TTIP on the Synthesis of TiO2 Nanoparticles to Improve the Performance of DSSC with Beta-Carotene as Sensitizer

TiO2 nanoparticles have been successfully synthesized using the sol-gel method with main materials of titanium tetraisopropoxide (TTIP) and HClO4 solutions. Mass ratios (Rw) of aquadest and TTIP were 0.85, 2.00, and 3.50 which were going to be investigated in crystallization of TiO2 phases. Pre-heating was performed on TiO2 at 60°C for one day then it was annealed at 150°C for 3 hours. The DSSC structure was formed by using the synthesized-TiO2 as semiconductor material and beta-carotene as dye sensitizer. The x-ray diffraction (XRD) spectrum indicated that TiO2 peaks had anatase phases on crystal orientation of (101), (004), and (200) while TiO2 of rutile phase only appeared on orientation of (211). The highest intensity for all Rw was dominated by (101) anatase phase. From XRD spectrum data of (101) peak, the Scherrer’s method predicted that crystal size of TiO2 was 3.48 nm, 4.36 nm, and 4.47 nm for Rw of 0.85, 2.00, and 3.50, respectively. The Tauc’s method was applied on the UV-Vis data that predicted the bandgap energy (Eg) of TiO2 for Rw of 2.00 (Eg=3.14 eV) was higher than Rw of 0.85 (Eg=3.02 eV) and 3.50 (Eg=3.04 eV). The I-V characteristic calculation of DSSC structures were obtained that the efficiency optimum is 0.01% for Rw of 2.00. It is considered that bandgap energy value correlated to stability of Ti-OH bonds that caused the exited-electrons are easily injected to conduction band of TiO2. The performance of DSSC using the synthesized-TiO2 which consists of anatase and rutile can be improved about ten times compared to that using the pure-TiO2 rutile.

Electrospinning Titanium Dioxide (TiO2) nanofiber for dye sensitized solar cells based on Bryophyta as a sensitizer

From an engineering and economic perspective, immobilized TiO2 nanocatalysts are preferred in a variety of applications. In this study, TiO2 polymer solution was synthesized using ethanol, acetic acid, polyvinylpyrrolidone (PVP), and titanium tetra isopropoxide (TTIP). TiO2 solution was deposited on the FTO substrate by electrospinning method to obtain nano-sized layer. Capillary of syringes given a positive DC voltage of 6 kV to produce nanofiber, then annealed at 450 °C for 3 hours. Chlorophyll has obtained from extracted moss through a chromatographic process to used for dye. TiO2 nanofiber layer manufactured with varied by time and characterized by UV-Vis and IV-meter. The result exhibited a maximum efficiency of 0,0036% and significant absorption at 350 nm-500 nm wavelength.

Comparison of Titanium Dioxide (TiO2) nanoparticle-nanofiber and nanofiber-nanoparticle on the application of dye-sensitized solar cell (DSSC)

Dye-sensitized Solar Cell (DSSC) is a solar cell that has great potential in the future because of the cheaper cost of fabrication and environmentally friendly basic ingredients. This study aims to determine the effect of type of screen on the TiO2 layer as the active electrode DSSC. The active electrode TiO2 based DSSC fabricated by the method of double layer. Efficiency Dye-sensitized Solar Cell (DSSC) can be obtained from the current-voltage curve I-V meter. Nanofiber on the nanoparticles can reach a highest efficiency of DSSC about 0,015%. The second variation of between nanofiber-nanoparticle layering, and nanoparticle-nanofiber, it appears that the nanofiber layer of nanoparticles above, no significant changes, namely in 10 minutes η = 0.014965; 15 minutes η = 0.011021 and 20 minutes η = 0.013332. This is demonstrated by the nature of the dominant nanofiber as a photon trap covered by the nature of the dominant nanoparticles absorb the dye, so that overtime does not affect the incoming electron. While the results of nanofiber layer on the nanoparticles changed significantly in the variation of 20 minutes, ie η = 0.00283. You can also see the most optimum time was 15 minutes, which is η = 0.01559. This may be due in this 15 minute nanofiber coating has a thickness that is optimum so that electrons can reach the electrode diffuse due to the interaction between photons and the dye more.

Effect of sintering temperatures and screen printing types on TiO2 layers in DSSC applications

Dye-Sensitized Solar Cell (DSSC) is a candidate solar cell, which has a big potential in the future due to its eco-friendly material. This research is conducted to study the effect of sintering temperature and the type of screen-printing toward the characteristics of TiO2 layer as a working electrode in DSSC. TiO2 layers were fabricated using a screen-printing method with a mesh size of T-49, T-55, and T-61. TiO2 layers were sintered at temperatures of 600°C and 650°C for 60 min. DSSC structure was composed of TiO2 as semiconductors, ruthenium complex as dyes, and carbon as counter electrodes. The morphology of TiO2 layer was observed by using Nikon E2 Digital Camera Microscopy. The efficiencies of DSSC were calculated from the I-V curves. The highest efficiency is 0.015% at TiO2 layer fabricated with screen type T-61 and at a sintering temperature of 650°C.Dye-Sensitized Solar Cell (DSSC) is a candidate solar cell, which has a big potential in the future due to its eco-friendly material. This research is conducted to study the effect of sintering temperature and the type of screen-printing toward the characteristics of TiO2 layer as a working electrode in DSSC. TiO2 layers were fabricated using a screen-printing method with a mesh size of T-49, T-55, and T-61. TiO2 layers were sintered at temperatures of 600°C and 650°C for 60 min. DSSC structure was composed of TiO2 as semiconductors, ruthenium complex as dyes, and carbon as counter electrodes. The morphology of TiO2 layer was observed by using Nikon E2 Digital Camera Microscopy. The efficiencies of DSSC were calculated from the I-V curves. The highest efficiency is 0.015% at TiO2 layer fabricated with screen type T-61 and at a sintering temperature of 650°C.

The study of FTO surface texturing fabrication using Argon plasma etching technique for DSSC applications

This paper is aimed to investigate the fabrication of the fluorine-doped tin oxide (FTO) texturing by using Argon (Ar) plasma etching. The pressure and temperature of Ar gas during plasma etching were 1.6 mbar and 240-285oC, respectively. The plasma etching time was varied from 3 and 10 min. We also prepared without etching samples as reference. UV-Vis spectrophotometer showed that the transmittances of etching samples are higher than the without etching samples. The root mean square roughness (Rq) of etching samples are lower than the without etching samples. It is considered that the Ar ions bombardment can modify the FTO surfaces. However, the etching time does not significantly affect the FTO surfaces for 3 min and 10 min. The Rq of the without etching sample, the etching sample for 3 min, and the etching sample for 10 min are 11.697 nm, 9.859 nm, and 9.777 nm, respectively. These results are good agreement with the four point probe measurement that indicated that the sheet resistance (RS) for each the without sample, the etching sample for 3 min, and the etching sample for 10 min are 16.817 Ωsq, 16.067 Ω/sq, and 15.990 Ω/sq. In addition, the optical transmittance of the etching sample for 3 min and the etching sample for 10 min at wavelengths of 350 - 850 nm are almost similar. This is evidence that the etching time below 10 min cannot significantly change the morphology, optical and electrical properties.