Perspectives for dye-sensitized nanocrystalline solar cells

Abstract

The dye‐sensitized solar cells (DYSC) provides a technically and economically credible alternative concept to present day p–n junction photovoltaic devices. In contrast to the conventional systems, where the semiconductor assumes both the task of light absorption and charge carrier transport, the two functions are separated here. Light is absorbed by a sensitizer which is anchored to the surface of a wide band gap semiconductor. Charge separation takes place at the interface via photo‐induced electron injection from the dye into the conduction band of the solid. Carriers are transported in the conduction band of the semiconductor to the charge collector. The use of transition metal complexes having a broad absorption band in conjunction with oxide films of nanocrystalline morphology permits the harvesting of a large fraction of sunlight. Near‐quantitative conversion of incident photons into electric current is achieved over a large spectral range extending over the whole visible region. Overall solar (standard AM1·5) to electric conversion efficiencies over 10% have been reached. There are good prospects for producing these cells at a lower cost than conventional devices. Here we present the current state of the field. We shall discuss new concepts of the dye‐sensitized nanocrystalline solar cell (DYSC), including solid heterojunction variants, and analyze the perspectives for future development of the technology into the next millennium. Copyright © 2000 John Wiley & Sons, Ltd.

Electrospun Carbon Nanofibers as Low-Cost Counter Electrode for Dye-Sensitized Solar Cells

“…Since J 0 is typically regarded as a measure of recombination in the device, this indicates that the ECN-based cells had a comparable recombination as that of the Pt-based devices. Previous studies have shown that charge recombination in DSCs at the FTO/TiO 2 and TiO 2 /electrolyte interface can cause a loss in V oc − . The observation that the ECN based DSCs had a V oc similar to that of the Pt-based devices further confirmed that the ECN counter electrodes do not affect recombination in the DSCs even at a large counter electrode thickness of ∼24 μm.…”

Efficiency Improvement of DSSC Photoanode by Scandium Doping of Mesoporous Titania Beads

“…17 The value of ϕ B is comparable with barriers of nanostructured anatase with noble metals such as Au, 37 Pt, 38 and Pd, 39 where ϕ B is 0.9, 1.0, and 0.85 eV, respectively. Just to check the consistency within the present findings, Table 2 compares the calculated values of V OC by the diode equation 40 = −…”

“…The value of ϕ B is comparable with barriers of nanostructured anatase with noble metals such as Au, Pt, and Pd, where ϕ B is 0.9, 1.0, and 0.85 eV, respectively. Just to check the consistency within the present findings, Table compares the calculated values of V OC by the diode equation V OC = k normalB T e .25em ln ( J SC J 0 − 1 ) where J SC is the short circuit current density (third column in Table ). The values are comparable, and the minimum difference is just 12 mV at 0.2 at.…”

Photovoltaic properties of dye sensitised solar cells using TiO 2 nanotube arrays for photoanodes: Role of hydrochloric acid treatment

“…It is well known that the dye molecules are adsorbed on the surface of TiO 2 via the interaction between hydroxyl groups on the TiO 2 surface and the carboxylic anchoring groups residing on dye molecules [35][36][37][38]. Therefore, increasing hydroxyl groups on the TiO 2 surface has a positive effect on dye adsorption, which is in good agreement with the trend of dye adsorption.…”