Increasing the Efficiency of Organic Dye‐Sensitized Solar Cells over 10.3% Using Locally Ordered Inverse Opal Nanostructures in the Photoelectrode

Abstract

3D inverse opal (3D-IO) oxides are very appealing nanostructures to be integrated into the photoelectrodes of dye-sensitized solar cells (DSSCs). Due to their periodic interconnected pore network with a high pore volume fraction, they facilitate electrolyte infiltration and enhance light scattering. Nonetheless, preparing 3D-IO structures directly on nonflat DSSC electrodes is challenging. Herein, 3D-IO TiO 2 structures are prepared by templating with self-assembled polymethyl methacrylate spheres on glass substrates, impregnation with a mixed TiO 2 :SiO 2 precursor and calcination. The specific surface increases from 20.9 to 30.7 m 2 g −1 after SiO 2 removal via etching, which leads to the formation of mesopores. The obtained nanostructures are scraped from the substrate, processed as a paste, and deposited on photoelectrodes containing a mesoporous TiO 2 layer. This procedure maintains locally the 3D-IO order. When sensitized with the novel benzothiadiazole dye YKP-88, DSSCs containing the modified photoelectrodes exhibit an efficiency of 10.35% versus 9.26% for the same devices with conventional photoelectrodes. Similarly, using the ruthenium dye N719 as sensitizer an efficiency increase from 5.31% to 6.23% is obtained. These improvements originate mainly from an increase in the photocurrent density, which is attributed to an enhanced dye loading obtained with the mesoporous 3D-IO structures due to SiO 2 removal.

Benzothiadiazole-based photosensitizers for efficient and stable dye-sensitized solar cells and 8.7% efficiency semi-transparent mini-modules

“…From 1, 6-bromo-4,4-bis(4-hexylphenyl)-4H-indeno [1,2-b]thiophene, 2 can be obtained via Grignard reaction and cyclization under acidic conditions. 30 Applying the same approach starting from 8 afforded compound 9. The triarylamine units 3, 4 and 10 were obtained via Buchwald-Hartwig cross-coupling reaction using unsubstituted or alkoxysubstituted diphenylamine.…”

“…This dye showed an efficiency of over 9% in DSSCs fabricated with classical architectures, and up to 10.3% with inverse opals-based electrodes. 30 Consequently, in this work, we investigate further the performance of YKP-88 and report the synthesis of four new analogue compounds whose chemical structures are tuned with the goal to shi its Internal Charge Transfer (ICT) absorption band towards lower energy wavelengths while keeping control of the energy levels of the frontier orbitals. Our objective was to prove efficient and stable dyes following this molecular concept while obtaining various colours.…”

Near infrared organic photodetectors based on enhanced charge transfer state absorption by photonic architectures

“…26 Major accomplishments have been achieved already in photovoltaics by structuring the device with photonic crystals. [27][28][29][30] In the case of 2D photonic crystals, its periodic structure diffracts incident light and enhances the optical path within the active layer, thus rendering higher efficiencies. In this work we will provide our photodetector with a back-electrode structured as a 2D photonic crystal engineered to couple incident light to photonic modes with enhanced electric field concentration in the active medium at those wavelengths of interest for the CTS absorption effect.…”

Enhancing Charge Transfer and Photoelectric Characteristics for Organic Solar Cells

“…The diversity of sensitizers has always been a research hotspot in the field of DSSCs, and the performance of sensitizers represented by D-π-A type structure is particularly outstanding, which has been unanimously recognized by the academic community [6][7][8]. Xu et al [9] synthesized a new sensitizer with D-π-A structure and applied it to the modified photoanode and found that the photoanode with 3D inverse opal nanostructure was more favorable to the photoelectric properties of DSSC. Huang and his collaborators [10] synthesized two novel π-conjugated moieties that could be part of π-bridge for the construction of D-π-A-configured photosensitizers for DSSC applications.…”