%0 Thesis
%A Riquelme Expósito, Antonio Jesús
%T Experimental characterization and numerical modeling of ionic and electronic dynamics in nanostructured hybrid materials for photoconversion
%D 2022
%U http://hdl.handle.net/10433/14573
%X The development of alternative, low emissions energy sources has gainedimportance for society as the worldwide energy demand increases whilethe environmental impact of the accumulated use of fossil fuels becomesmore evident, reflected in climate change. As a response to this problem, thescientific community has focused on researching new energy sources. Oneof the technologies that has driven more attention is photovoltaic technologyto directly exploit the vast amount of energy reaching the Earth¿s surface assunlight. While silicon-based solar cells have dominated the photovoltaiclandscape for many years, the search for alternatives decreasing the needfor scarce materials or high energy cost manufacturing processes has ledto the development of the third-generation photovoltaics. In this context,dye-sensitized solar cells were a breakthrough in the field as they are made ofabundant and cheap materials and comprise relatively simple manufacturingprocesses.Furthermore, their adaptability and variety of elements make them veryappealing for emerging markets and new applications such as buildingintegrated photovoltaics or indoor applications. Perovskite solar cells rapidlyemerged from a particular application of dye-sensitized solar cells to abrand new photovoltaic technology in their own right, reaching outstandingefficiencies thanks to their excellent optoelectronic properties. In addition,the natural abundance of the precursors involved in the synthesis of thematerial also makes them an up-and-coming technology. However, the lackof stability under environmental conditions, the use of expensive materials,along with other technical limitations such as the need for inert environmentsin the manufacturing process have kept this technology from deep marketpenetration and widespread implementation. For this reason, fundamentalknowledge of the electronic and ionic properties behind the positive andnegative aspects of these materials is highly needed to help optimize them.The main aim of this thesis is to understand the ionic and electronicdynamics and the physicochemical processes that determine the photovoltaicperformance under operating conditions and the long-term stability of thesehybrid nanostructured materials. To accomplish this objective, small-signalperturbation optoelectronic techniques have been used, together with numer-ical drift-diffusion simulations. Considered together, it helps to cast lighton the electronic and ionic phenomena that determine the functioning ofthe device as well as the key interplay between the two: electronics andionics. In this context, the similarities between already understood systemssuch as normal dye-sensitized solar cells with the materials studied in thisthesis are used to identify and interpret the different signals obtained fromsmall signal perturbation optoelectronic techniques. In addition, combiningthese experimental techniques with numerical simulations has proven tobe, in this thesis, an instrumental approach to understanding the physicalmeaning of the elements identified in experimental spectra allowing for theirinterpretation and understanding their role in determining the photovoltaicproperties of the device under operation conditions.
%K Energía solar
%K Conversión de energía
%K Química física
%K Fotoconversión
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