Ruthenium Polypyridyl TG6 Dye for the Sensitization of Nanoparticle and Nanocrystallite Spherical Aggregate Photoelectrodes

Abstract

A ruthenium polypyridyl dye containing a hexasulfanyl-styryl modified bipyridyl group as ancillary ligand, coded TG6, is investigated as a sensitizer for ZnO-based dye-sensitized solar cells (DSSCs). The advantages of this dye are a broad wavelength absorption spectrum, a large loading in ZnO photoelectrodes, a significantly larger extinction coefficient compared to more classical Ru-polypyridyl dyes, and the formation of less agglomerate in the pores of the ZnO layers. TG6 has been used to sensitize ZnO nanorod particle layers of high structural quality and ZnO layers made of submicrometer spheres composed of aggregated nanocrystallites and that develop an internal surface area. The latter are highly light-scattering in the visible wavelength region but more difficult to sensitize correctly. The TG6 dye has been compared with the metal-free D149 dye and has been shown more efficient for photoconversion. The best performances have been obtained by combining TG6 with the nanorod layer, the optimal power conversion efficiency being measured at 5.30% in that case. The cells have been investigated by impedance spectroscopy over a large applied voltage range. We especially show that the submicrometer sphere layers exhibit lower conductivity and lower charge collection efficiency as compared to the nanorod particle ones.

Photocurrent Enhancement from Solid-State Triplet–Triplet Annihilation Upconversion of Low-Intensity, Low-Energy Photons

“…TiO 2 layer thicknesses of 5 and 10 μm were found to be optimal for demonstrating performance enhancement from TTA film incorporation, as discussed below. To verify the quality of our devices, we constructed a DPSC with a 25 μm TiO 2 layer, which yielded an efficiency of 5%, which is consistent with or better than prior reports. − Interestingly, the thinner films optimized for demonstrating the TTA-UC enhancement yielded only slightly lower efficiencies of 4.3% and 4.7% for the 5 and 10 μm thick layers, respectively.…”

“…As shown in Figure S3, the D131 molecule has a typical donor−π bridge–acceptor structure in which the indoline unit acts as the donor moiety, while cyanoacrylate acts as both the acceptor and the anchoring group to the surface of TiO 2 . − Its absorption onset wavelength is 530 nm, which corresponds to a HOMO–LUMO gap of ∼2.34 eV. Under operating conditions in a DSPC, the external quantum efficiency (EQE) spectrum, referring to the number of incident photons at a given wavelength that successfully produce charged carriers, broadens and the absorption onset is considerably red-shifted to 575 nm (Figure a).…”

Synthesis and characterization of zinc oxide nanoparticles by using polyol chemistry for their antimicrobial and antibiofilm activity

“…The basic approach for addition of sodium acetate was the addition of excess acetate ions that gives different particle morphologies than the particles synthesized in absence of sodium acetate. Sodium acetate causes a weak hydrolyzation, which controls the release rate of OH − [36] , [37] , [38] , [39] , [40] , [41] , [42] .…”

ZnO Nanorods: An Advanced Cathode Buffer Layer for Inverted Perovskite Solar Cells

“…The conductivity measurements showed that the NR layers were more conducting than the aggregate particles. The electrical connections were much better for the NRs compared to the submicrometer spheres. , Moreover, a metal oxide-based composite, as well as the polymer conjugated, was emerged as CBLs in inverted PSCs, in which polymers can passivate the surface defect of metal oxides. − The device output based on these composites is improved in comparison with pure metal oxides because of the increased electron selectivity of such composites. According to the previous study, Jia et al reported a cathode buffer interfacial layer composite from ZnO as well as PFN (poly­[(9,9-bis­(3′-( N , N -dimethylamion)­propyl)-2,7-fluorene)- alt -2,7-(9,9-dioctyl)-fluorene]) based on PSCs.…”

“…The electrical connections were much better for the NRs compared to the submicrometer spheres. 37,38 Moreover, a metal oxide-based composite, as well as the polymer conjugated, was emerged as CBLs in inverted PSCs, in which polymers can passivate the surface defect of metal oxides. 39−41 The device output based on these composites is improved in comparison with pure metal oxides because of the increased electron selectivity of such composites.…”