Interfaces in Dye-Sensitized Electrodes : From Fundamental Understanding to Devices

• Renewable energy solutions are vital in realising a more equitable and sustainable future. Among several solar light harvesting and storage technologies, dye-sensitized electrodes offer a cost-effective and flexible solution for solar cells or solar fuel devices. In order to enhance their solar conversion efficiency, however, the understanding of charge transfer pathways, particularly at the dye-sensitized surface, is crucial. Surface properties and interfacial processes have a great effect on the final device and are the overarching theme of this thesis.Firstly, intermolecular charge transfer across dye-sensitized surfaces was investigated, which play a role in both facilitating charge accumulation and affecting recombination rates and are therefore pivotal factors influencing solar cell efficiencies. Specifically, investigations on nickel oxide (NiO) and ZrO2 surfaces elucidate charge transfer mechanisms across the surface and their dependence on solvent properties, offering possible pathways for optimizing device performance.Due to their significance on dye-sensitized photocathodes, the chemical nature of NiO surface states was explored as they are known to affect charge recombination and the dye-regeneration processes. Spectroscopic insights during controlled atmosphere experiments highlight the influence of surface species generated by oxygen and water molecules on the electronic properties of NiO, particularly of hydroxide and oxygen-related species.Thirdly, the design and characterization of the first reported solid-state p-n tandem dye-sensitized solar cell was demonstrated. Such a cell can surpass the voltage limitations observed in liquid tandem cells and could achieve an open-circuit voltage of 1.4 V. These tandem cells hold promise for applications in solar fuel production, where high potential differences are essential for driving chemical reactions.

Ämnesord

NATURVETENSKAP  -- Kemi -- Fysikalisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Physical Chemistry (hsv//eng)

Nyckelord

Photovoltaics

dye-sensitized

charge transfer

liquid-solid interface

surface properties

tandem-cells

Chemistry with specialization in Physical Chemistry

Kemi med inriktning mot fysikalisk kemi

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