Su-Bin Lee

Synthesis, Characterization, and Photovoltaic Properties of Soluble TiOPc Derivatives

We have synthesized soluble TiOPc derivatives containing alkoxy groups for use as additives in dye-sensitized solar cells (DSSCs). The DSSC devices containing these TiOPc derivatives exhibited short-circuit current densities of 8.49~10.04 mA/cm2 and power conversion efficiencies of 2.73~3.62 % under AM 1.5 illumination and 100 mW/cm2 irradiation.

Photovoltaic Properties of Dye-Sensitized Solar Cells Using Glycerol-Modified PEDOT:PSS

In this study, we fabricated Dye-Sensitized Solar Cell (DSSC) device using poly(3,4-ethylenedioxythiophene):poly(styrenesulphonic acid) (PEDOT:PSS) or glycerol-modified PEDOT:PSS (G-PEDOT:PSS) as hole conducting materials. In SnO2:F/TiO2/Dye/PEDOT:PSS (or G-PEDOT:PSS)/Pt device system, in order to increase the ionic conductivity, the addition of ionic liquid into PEDOT:PSS solution resulted in the increase of power conversion efficiency of devices. We investigated photovoltaic characteristics of three type devices of SnO2:F/TiO2/Dye/G-PEDOT:PSS/Pt system according to glycerol concentration in PEDOT:PSS. The SnO2:F/TiO2/Dye/G-PEDOT:PSS/Pt device with 6 wt% glycerol in PEDOT:PSS showed the best result on 2.62% of the power conversion efficiency. The open-circuit voltage (Voc) of this device was 0.82 V, the short-circuit current density (Jsc) was 5.48 mA/cm2, and fill factor (FF) was 0.59.

Effect of Etched Substrates in Long-Term Stability Testing of Dye-Sensitized Solar Cells

The dye-sensitized solar cells (DSSCs) examine long-term stability tests were prepared to SnO2:F (FTO) glass substrates patterned by the etching method were applied to the electrode on the device using polyethyleneglycol (PEG) electrolyte. We investigated the effect of patterned SnO2:F (FTO) glass substrates on the power conversion efficiency and long-term stability of DSSCs. The patterned devices maintained over 83% of its initial overall power conversion efficiency after 720 hours aging at room temperature, while the devices using non-patterned FTO glass substrates showed drastic decrease in performances.

Dye-sensitized solar cells based on poly(ethylene glycol) electrolyte containing oxotitanium(IV) 5,10,15,20-tetrakis(p-toyl)porphyrin

We have focused on the synthesis and photovoltaic properties of oxotitanium(IV) 5,10,15,20-tetrakis(p-toyl) porphyrin (TiO-TTP) as an additive in the dye-sensitized solar cell (DSSC). The chemical structure of TiO-TTP synthesized was characterized by FT-IR and 1H-NMR spectroscopy. We have prepared the DSSC device, using N3 dye as a photosensitizer, sandwiched with a TiO 2 -deposited electrode and a Pt-coated electrode as two electrodes. In order to investigate the photovoltaic effects of the DSSC devices, the FTO/TiO 2 /Dye/Electrolyte/Pt device was fabricated by using the poly(ethylene glycol) (PEG) electrolyte based on TiO-TTP as the additive. The photovoltaic performances of the DSSC devices were measured by solar simulator under 100 mW/cm2 at AM 1.5. The J sc is 7.75 mA/cm2 and the V OC is 0.76 V and the FF is 0.62, leading to a calculated power conversion efficiency of 3.60 %. When TiO-TTP was introduced into the PEG electrolyte, the η of DSSC device was shown remarkably a high value compared with the value of that without TiO-TTP or metal free TTP. This result was caused by the adsorption on the interface between nanocrystalline porous TiO 2 films and PEG electrolyte by TiO center of TiO-TTP.