Conventional dye-sensitized solar cells (DSSCs) require two transparent conductive oxide (TCO) glasses as working and counter electrodes and are one of the most costly components posing an appreciable cost burden for production and commercialization. To circumvent this issue, we propose a TCO-free device structure utilizing titanium (Ti) sheets as a substitute for TCO. This back contact device structure not only allows the removal of the costly TCO component from the working electrode but also enhances the extent of photons absorbed by the photoanode. A flat titanium sheet with microholes (FTS-MH) was successfully applied to fabricate cylindrical TCO-free-DSSCs) with a titanium sheet as a back contact electrode. When the H2O2 surface-treated FTS-MH substrate generating dense anatase TiO2 nanosheets was used as a photoanode, there was a pronounced improvement in efficiency from 5.76% to 8.59%. This was mainly attributed to the lower interfacial resistance facilitated by improved electrical contact between the conducting FTS-MH substrate and mesoporous TiO2 layer since enhancement in the dye loading was only 8.6%.
Grätzel solar cells are reported in a transparent conducting oxide-less (TCO-less) back-contact dye-sensitized solar cell (BC-DSC) architecture using a stainless steel mesh-protected working electrode along with nanoporous TiO2 semiconductor and metal-free D205 dye. Liquid electrolytes play a significant role for the dye regeneration in the working operation of TCO-less BC-DSCs; therefore, we report the effectiveness of two different commonly utilized electrolytes (iodine- and cobalt-based redox shuttles) for the construction and performance of TCO-less dye-sensitized solar cells (DSCs). Differential performance of DSCs thus fabricated was interpreted utilizing impedance spectral and lifetime analysis. It was found that although utilization of cobalt bipyridyl complex-based electrolyte was able to harvest higher photons in the lower wavelength region (330 to 430 nm) as compared to its iodine electrolyte counterparts, hampered dye regeneration due to reduced driving force and slower ion diffusion in combination with higher charge transport resistance at TiO2 / dye / electrolyte was responsible for relatively hampered photovoltaic performance at peak absorption.
A flat titanium sheet with microholes (FTS-MH) has been utilized to fabricate transparent conductive oxide-less dye-sensitized solar cells (TCO-less DSSCs) in back contact device architecture. Utilization of FTS-MH to fabricate a TCO-less photoanode offers several advantages in terms of simplicity and ease of fabrication as compared with the TCO-less DSSCs structure reported previously. Hydrogen peroxide (H2O2) surface treatments on FTS-MH have shown important factors to enhance the photoanode properties. H2O2 surface treatment is able to change the surface morphology of FTS-MH, and the created anatase titanium dioxide (TiO2) nanostructures increase the surface contact between the FTS-MH and the coated mesoporous TiO2. Electrochemical impedance investigations reveled that improvements of the FTS-MH/TiO2 and TiO2/dye/electrolyte interface led to hampered charge recombination resulting in enhancement of both short-circuit current density and open-circuit voltage, respectively. Even after removal of both TCO layers, our complete TCO-less DSSCs exhibited a power conversion efficiency of 7.25% under simulated solar irradiation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.