Improvement in Energy Conversion Efficiency by Modification of Photon Distribution within the Photoanode of Dye-Sensitized Solar Cells

Abstract

The dye-sensitized solar cell (DSSC) is a potential alternative to the widely used Si-based solar cell, with several advantages including higher energy conversion efficiency under weak and indirect illumination conditions, and the possibility of practical application in urban life due to their exterior characteristics. However, despite these advantages, the energy conversion efficiency of DSSCs has remained low at ∼10%. To improve the efficiency of DSSCs, research has been done on modifying the materials used in DSSC component parts, such as the photoanode, electrolyte, and counter electrode. Another approach is to modify the photoanode to increase the diffusion coefficient, reduce the recombination rate, and enhance the light behavior. One of the most popular methods for improving the efficiency of DSSCs is by trapping and dispersing the incident light using a scattering layer. Use of a scattering layer has shown various and interesting results, depending on the application, but it is currently used only in a simple form and there has been no deep research on the further potential of the scattering layer. In this study, the scattering center was introduced to maximize the effect of scattering. Light distribution near the scattering center, within or on the photoanode, was investigated using finite differential time domain (FDTD) numerical methods. Based on the FDTD analysis, an optimized, dome-shaped three-dimensional modified structure of a transparent photoanode with minimized scattering centers was introduced and indicated the possibility of modifying the photon distribution in the photoanode to enhance the performance of DSSCs. In addition to using the scattering center, we have introduced the structure of the dome-shaped three-dimensional structure to utilize the light distribution within the photoanode. This novel three-dimensional transparent photoanode and scattering center design increased the energy conversion efficiency of DSSCs from 6.3 to 7.2%. These results provide a foundation for investigating the role of the scattering center via further in-depth research. This new three-dimensional photoanode design provides a means to overcome the previous limitations on DSSC performance.

Dye-Sensitized Solar Cells: Fundamentals and Current Status

“…The addition of synthesized Au NPs to the Z907 dye increased the absorption of the Z907 dye, thus achieving ɳ = 1.284% for the cell without Au NPs and 2.357% for the cell incorporating the Au NPs. Recently, in 2018, a novel 3-D transparent photoanode and scattering center design was applied as to increase the energy conversion efficiency from 6.3 to 7.2% of the device [ 317 ] because the plasmonics plays an important role in the absorption of light and thus, the application is developing at a very fast pace and grabbing a lot of attention worldwide in the last few years. Recently, a study on incorporation of Mn 2+ into CdSe quantum dots was carried out by Zhang and group [ 318 ].…”

Current Status of Emerging PV Technologies: A Comparative Study of Dye-Sensitized, Organic, and Perovskite Solar Cells

“…The addition of the synthesized gold nanoparticles to the dye resulted in an increase in device efficiency from 1.284% to 2.357%, due to increased light absorption from the gold nanoparticles. More recently, Sim et al [59] achieved an increase in device efficiency from 6.3 to 7.2% by developing a three-dimensional transparent photoanode and a scattering layer, which was used to trap and disperse incident light within the device.…”

Bifacial dye-sensitized solar cells for indoor and outdoor renewable energy-based application

“…In view of this, with the goal of increasing the quantity of light harvesting, and hence the PCE value, several approaches like complementary dyes combination, either as a dye cocktail or arranged in multiple dye layers, the use of functionalized organic dye molecules in a rigid panchromatic structure, 19 as well as strategies to enhance the optical path of incident light, via porous back-scattering films or submicron particles of high refractive index, have been considered. 20,21 Strong interest has also been paid to the development of tandem-DSSCs (T-DSSCs) configuration, 22 an alternative option to increase the device efficiency beyond the thermodynamic limit of single junction. However, although great steps have been made, actual results are still not so satisfactory.…”

“…16 With common and commercial red and orange dyes, DSSCs have reached an average visible transmittance (AVT) of 20-30%,17 while an outstanding AVT higher than 60%,18 has been reported using a select dye system which absorbs in the UV and near-IR region. However, though significant breakthroughs have been obtained and years of thriving growth can be expected, the need to improve the cell's PCE beyond 20% is of critical importance for the scale-up industrial applications of this technology.In view of this, with the goal of increasing the quantity of light harvesting, and hence the PCE value, several approaches like complementary dyes combination, either as a dye cocktail or arranged in multiple dye layers, the use of functionalized organic dye molecules in a rigid panchromatic structure,19 as well as strategies to enhance the optical path of incident light, via porous back-scattering films or submicron particles of high refractive index, have been considered 20,21. Strong interest has also been paid to the development of tandem-DSSCs (T-DSSCs) configuration,22 an alternative option to increase the device…”