Thiazolo[5,4-d]thiazole-based organic sensitizers with improved spectral properties for application in greenhouse-integrated dye-sensitized solar cells

Abstract

Semitransparent dye-sensitized solar cells (DSSCs) for greenhouse integration were manufactured by using especially designed organic dyes featuring different heterocyclic moieties integrated into a thiazolo[5,4-d]thiazole-molecular scaffold.

D–A–π–A organic dyes with tailored green light absorption for potential application in greenhouse-integrated dye-sensitized solar cells

“…Since the separation of 3 and 3-iso was not possible, we abandoned the convergent synthetic pathway and prepared intermediate 4 through direct arylation of 1 with 4,7-dibromo-2,1,3-benzothiadiazole under our previously reported, optimized conditions (Scheme 1, path b). 33 In this case, improved regioselectivity was observed which, together with the successful separation of the two possible regioisomers by ash column chromatography, allowed us to recover pure aldehyde 4 in 39% yield. Finally, subjecting compound 4 to a classic Suzuki-Miyaura cross-coupling with p-N,N-(diphenylamino)phenylboronic acid easily allowed the placement of the triphenylamine group leading to compound 3.…”

“…The reaction was carried out using the optimized procedure that we previously reported for a different heterocyclic core. 33,55 The desired advanced intermediate 8 was thus obtained in just one step, with 26% yield. It is noteworthy that neither a fresh catalyst nor an additive was added for the second C-H activation step with 4-bromobenzaldehyde, therefore both transformations could be promoted by the initial catalytic load.…”

“…1) specically designed for improving the light absorption capability in the green part of the visible spectrum while maintaining good transparency in the blue and red regions. 33 Such dyes were used to build semitransparent DSSCs, yielding 5.6-6.1% power conversion efficiencies. Dyes like TTZ8-12 are based on pushpull D-p-A structures, in which a donor group (D) is connected to an acceptor/anchoring group (A) through a conjugated bridge (p, Fig.…”

“…35 Aiming to disclose a new series of DSSC sensitizers for greenhouse integration, we decided to follow the latter approach and chose the well-known 2,1,3-benzothiadiazole (BTD) as an internal electron-accepting moiety, since it has already been shown to red-shi the UV-Vis absorption spectrum of the resulting compounds once introduced next to a donor group in a D-A-p-A structure. [36][37][38][39][40][41] In addition, we chose the dithieno[3,2-b:2 0 ,3 0 -d]pyrrole (DTP) 33 unit as the electrondonating group to be connected to BTD, since it had already been successfully inserted in DSSC sensitizers presenting two main favourable features: it can be easily modied by introducing different substituents on the bridging nitrogen, allowing the tuning of important properties such as the solubility in organic solvents; it possesses a wide p-conjugation due to the co-planarity of its bridged tricyclic system. Thus, in this paper, we report the design and preparation of three new D-A-p-A organic photosensitizers, named BTD-DTP1, BTD-DTP2 and BTD-DTP3, all containing the benzothiadiazole (BTD) scaffold and incorporating differently substituted dithieno[3,2-b:2 0 ,3 0 -d] pyrrole (DTP) p-linkers (Fig.…”

Enhanced performance of dye-sensitized solar cell with thermally stable natural dye-assisted TiO2/MnO2 bilayer-assembled photoanode

“…The absorption defect of the M. penduliflorus flower-extracted dye starts from 550 nm onward [18]. The performance of the DSSC can be compensated introducing a scattering layer or interfacial modification in the photoanode and concomitantly improves the broader spectrum wavelength range of light absorption to make it suitable for outdoor application(s) [19,20]. The front side and back side illumination for photovoltaic devices originate from the cost-effective perspective, as the higher percentage of the incident solar spectrum can be harvested without altering the cell area.…”