Toward nanostructured perovskite solarcells based on nanoporous anodic alumina technology,
- Autores: María del Pilar Montero Rama
- Directores de la Tesis: Lluís F. Marsal Garví (dir. tes.)
- Lectura: En la Universitat Rovira i Virgili ( España ) en 2020
- Idioma: español
- Tribunal Calificador de la Tesis: Josep Pallarès Marzal (presid.), Antonio Agustin Mihi Cervello (secret.), Franklin Jaramillo (voc.)
- Programa de doctorado: Programa de Doctorado en Tecnologías para Nanosistemas, Bioingeniería y Energía por la Universidad Rovira i Virgili
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
In the last decades, nanotechnology has been widely studied. It is due to the unique catalytic, electronic, magnetic, optoelectronic and mechanical properties. So, these nano-sized materials can be applied in several fields such as chemistry, sensors, biotechnology, electronics and so on.
Nowadays, nanotechnology research based on nanoporous materials synthesized by electrochemical techniques, such as nanoporous anodic alumina (NAA) is one of the most active. NAA manufactured by aluminium substrates anodization owns exceptional chemical, optical and mechanical properties, for example, chemical resistance, thermal stability, hardness, biocompatibility and large specific surface area. NAA is an excellent platform to develop sophisticated and relevant applications as selective molecular separation, chemical/biological sensing, catalysis, cell adhesion and culture, data storage, energy generation and storage, drug delivery and template synthesis.
NAA technology has evolved as one of the major topics in science today, offering exciting novel opportunities in the field of renewable energy manufacturing/conversion and storage. Focusing on the use of NAA as energy generation devices, it is essential that these devices also meet similar requisites of sustainability and efficiency, making the entire process of generation and consumption of energy as clean as possible.
On the other hand, currently, about 80% of global energy consumption, which includes providing 65% of global electricity generation originates from fossil fuels (coal, oil and natural gas). If society does not perform rapidly to decrease emissions of greenhouse gases, mainly carbon dioxide (CO2) released through the burning of fossil fuels, we will face disastrous consequences. Decreasing our need for these energy sources by switching to renewable sources like wind and solar, will let a noteworthy lessening in carbon emissions. Luckily, humanity is more and more becomes aware of the use of sustainable energy sources that keep the environment, such as solar energy.
The Sun is t he principal source of visible light and the most important source of radiant energy that hits the Earth. The total solar irradiance hitting the top of the Earth's atmosphere is around 1361 W/m2. This energy can be used by plants for the process of photosynthesis, for heating and for generating electricity. Currently, solar energy is one of the most significant renewable energy for achieving a sustainable future.
Due to the large absorption coefficient, suitable bandgap, excellent crystallinity and long carrier diffusion length of organic-inorganic hybrid perovskites (OIHPs), in the past years, they have drawn great research attention because for photovoltaic (PV) applications.
To decide the viability of the commercialization of PV technology, three factors are typically considered: cost, efficiency and stability. The power conversion efficiency (PCE) of a PV device is a measure of the percentage of light incident upon it that is converted into usable electricity. Perovskiter solar cell (PSCs) are predicted to be low-cost since their low material and fabrication costs. In a few years, its PCE almost reaches the value of silicon solar cells. PSCs efficiencies have increased from 2.2% in 2006 to 25.2% in 2020.However, stability still requires further development.
This thesis aim is focused on the use of NAA technology to develop nanostructured perovskite solar cells. NAA will provide the advantage of enhancing perovskite stability since the perovskite layer will be surrounded by the other layers and the nanopore walls. Therefore, first, the familiarization process with the manufacture and characterization of NAA, as well as of high-efficiency PSCs, by known standard methods were conducted.
NAA has not electric contact between the interior of the nanopores and the aluminium substrate. This is due to the as produce compact oxide layer (barrier layer) at the nanopore bottom. So, the first goal achieved is to remove this thick barrier layer under controlled anodization conditions. With this structural modification, electric contact between the aluminium of the NAA substrate and the possible infiltrated materials within the nanopores is reached.
Also, the objective of infiltrating the different materials that form the PCSs with a specific height and homogeneous among all the nanopores is studied and attained.
In this PhD essay, the design and fabrication of an energy generation device founded on nanostructured perovskite solar cells based on NAA technology are presented.
High-efficiency PSCs were first manufactured, using simple deposition methods: spin-coating and thermal evaporation. Most of these depositions were conducted in a N2-filled glovebox. The devices were characterized by the solar simulator (Abet Technologies model 11000 class type A, Xenon arc) and a Keithley 2400 Source-Measure Unit.
NAA was obtained by aluminium electrochemical anodization. The substrates were mainly characterized by Scanning Electron Microscopy.
The nanostructured perovskite solar cells were also manufactured by simple deposition methods such as spin-coating, drop-casting and thermal evaporation. Besides, most of these depositions were conducted in a N2-filled glovebox.
They were characterized by Scanning Electron Microscopy, Energy-Dispersive X-Ray Spectroscopy, Atomic Force Microscopy, Profilometry, X-ray diffraction and the solar simulator (Abet Technologies model 11000 class type A, Xenon arc) and a Keithley 2400 Source-Measure Unit.
