Multi-junction thin film solar cells for an optimal light harvesting
Thin film photovoltaics encompass a group of technologies able to harvest light within a few microns thickness. The reduced thickness allows a low cost of manufacture while making the films flexible and adaptable to different surfaces. This, combined with their low weight, positioned thin film solar...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2017 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/108231 |
| Acceso en línea: | https://hdl.handle.net/2117/108231 https://dx.doi.org/10.5821/dissertation-2117-108231 |
| Access Level: | acceso abierto |
| Palabra clave: | Cèl·lules solars Energia solar fotovoltaica Àrees temàtiques de la UPC::Física |
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Multi-junction thin film solar cells for an optimal light harvesting |
| title |
Multi-junction thin film solar cells for an optimal light harvesting |
| spellingShingle |
Multi-junction thin film solar cells for an optimal light harvesting Mantilla Pérez, Paola Cèl·lules solars Energia solar fotovoltaica Àrees temàtiques de la UPC::Física |
| title_short |
Multi-junction thin film solar cells for an optimal light harvesting |
| title_full |
Multi-junction thin film solar cells for an optimal light harvesting |
| title_fullStr |
Multi-junction thin film solar cells for an optimal light harvesting |
| title_full_unstemmed |
Multi-junction thin film solar cells for an optimal light harvesting |
| title_sort |
Multi-junction thin film solar cells for an optimal light harvesting |
| dc.creator.none.fl_str_mv |
Mantilla Pérez, Paola |
| author |
Mantilla Pérez, Paola |
| author_facet |
Mantilla Pérez, Paola |
| author_role |
author |
| dc.contributor.none.fl_str_mv |
Martorell Pena, Jordi |
| dc.subject.none.fl_str_mv |
Cèl·lules solars Energia solar fotovoltaica Àrees temàtiques de la UPC::Física |
| topic |
Cèl·lules solars Energia solar fotovoltaica Àrees temàtiques de la UPC::Física |
| description |
Thin film photovoltaics encompass a group of technologies able to harvest light within a few microns thickness. The reduced thickness allows a low cost of manufacture while making the films flexible and adaptable to different surfaces. This, combined with their low weight, positioned thin film solar cells as ideal candidates for building integrated photovoltaics. For the latter, organic solar cells (OSC) can provide a high quality semi-transparency that closely mimics the aesthetics of standard windows. Indeed, some unique features of organic solar cells make them the optimal solution for applications where standard Si technology cannot be used. However, for large-scale electricity production where efficiency is, perhaps, the most determining factor, newer thin film technologies like perovskites solar cells may be a more adequate option. At the moment of writing this thesis, state of the art efficiencies of single junction perovskites nearly double that of the best single junction organic solar cell. A limitation found in both technologies, especially in organics and to a lesser degree in perovskites, is the low mobility of the carriers. This, together with other processing shortcomings in the organic absorbers and perovskites limit their thickness to 100-130 nm, and 500-600 nm, respectively. In summary, light management must be an essential ingredient when designing device architectures to achieve the optimal performance in the specific application being considered. In this thesis, in order to achieve an optimal light harvesting and therefore increase the performance of thin film solar cells, we take two approaches. On one hand, we increase the total thickness of the absorber material used in the device without increasing the thickness of the single active material layer and, on the other hand, we combine complementary absorbers to cover a wider portion of the solar spectra. These approaches pose the double challenge of finding the optimal electromagnetic field distribution within a complicated multilayer structure containing two or more active layers, while at the same time implementing an effective charge collection or recombination in the intermediate layers connecting two adjacent sub-cells. In the case of OSC, we consider multi-junction cells where the same active material is used in all the junctions. This can be implemented by fabricating structures where the active layer thickness in each sub-cell does not exceed the 100 nm. For other types of thin film solar cells, we consider configurations using complementary absorbers. In both cases, but particularly in the former one, a systematic approach to optimize light absorption is needed. In order to obtain such optimal configurations, we implement an inverse integration approach combined with a transfer matrix calculation of the electric field. Furthermore, we develop several new approaches to optimize charge collection in the sub-cell interconnection layers which we apply to tandem, triple, 4-terminal and series-parallel configurations. The thesis has been organized into five chapters. Chapter 1 introduces concepts required for the development of the thesis work including the optical model. Chapter 2 describes the optical optimization and experimental implementation of current-matched multi-junction devices using PTB7:PC71BM, including applications. In order to profit from the advantage of electrically separated devices, Chapter 3 evaluates different types of 4-terminal architectures using PTB7:PC71BM and PTB7-Th:PC71BM. In one of the architectures we establish a serial-connection between sub-cells while in other we leave the sub-cells completely independent. Chapter 4 theoretically proposes a novel monolithic architecture combining perovskites and CIGS which does not require current-matching. Finally, in Chapter 5, an in-depth study of the semi-transparent inner electrodes is given that include vacuum-based and solution-processed layers. |
| publishDate |
2017 |
| dc.date.none.fl_str_mv |
2017 2017-04-24 2017 2017-10-02 |
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doctoral thesis http://purl.org/coar/resource_type/c_db06 VoR http://purl.org/coar/version/c_970fb48d4fbd8a85 |
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info:eu-repo/semantics/doctoralThesis |
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doctoralThesis |
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https://hdl.handle.net/2117/108231 https://dx.doi.org/10.5821/dissertation-2117-108231 |
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https://hdl.handle.net/2117/108231 https://dx.doi.org/10.5821/dissertation-2117-108231 |
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Inglés eng |
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Inglés |
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eng |
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open access http://purl.org/coar/access_right/c_abf2 http://creativecommons.org/licenses/by-nc-sa/4.0/ |
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info:eu-repo/semantics/openAccess |
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open access http://purl.org/coar/access_right/c_abf2 http://creativecommons.org/licenses/by-nc-sa/4.0/ |
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openAccess |
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application/pdf |
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Universitat Politècnica de Catalunya |
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Universitat Politècnica de Catalunya |
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reponame:UPCommons. Portal del coneixement obert de la UPC instname:Universitat Politècnica de Catalunya (UPC) |
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Multi-junction thin film solar cells for an optimal light harvestingMantilla Pérez, PaolaCèl·lules solarsEnergia solar fotovoltaicaÀrees temàtiques de la UPC::FísicaThin film photovoltaics encompass a group of technologies able to harvest light within a few microns thickness. The reduced thickness allows a low cost of manufacture while making the films flexible and adaptable to different surfaces. This, combined with their low weight, positioned thin film solar cells as ideal candidates for building integrated photovoltaics. For the latter, organic solar cells (OSC) can provide a high quality semi-transparency that closely mimics the aesthetics of standard windows. Indeed, some unique features of organic solar cells make them the optimal solution for applications where standard Si technology cannot be used. However, for large-scale electricity production where efficiency is, perhaps, the most determining factor, newer thin film technologies like perovskites solar cells may be a more adequate option. At the moment of writing this thesis, state of the art efficiencies of single junction perovskites nearly double that of the best single junction organic solar cell. A limitation found in both technologies, especially in organics and to a lesser degree in perovskites, is the low mobility of the carriers. This, together with other processing shortcomings in the organic absorbers and perovskites limit their thickness to 100-130 nm, and 500-600 nm, respectively. In summary, light management must be an essential ingredient when designing device architectures to achieve the optimal performance in the specific application being considered. In this thesis, in order to achieve an optimal light harvesting and therefore increase the performance of thin film solar cells, we take two approaches. On one hand, we increase the total thickness of the absorber material used in the device without increasing the thickness of the single active material layer and, on the other hand, we combine complementary absorbers to cover a wider portion of the solar spectra. These approaches pose the double challenge of finding the optimal electromagnetic field distribution within a complicated multilayer structure containing two or more active layers, while at the same time implementing an effective charge collection or recombination in the intermediate layers connecting two adjacent sub-cells. In the case of OSC, we consider multi-junction cells where the same active material is used in all the junctions. This can be implemented by fabricating structures where the active layer thickness in each sub-cell does not exceed the 100 nm. For other types of thin film solar cells, we consider configurations using complementary absorbers. In both cases, but particularly in the former one, a systematic approach to optimize light absorption is needed. In order to obtain such optimal configurations, we implement an inverse integration approach combined with a transfer matrix calculation of the electric field. Furthermore, we develop several new approaches to optimize charge collection in the sub-cell interconnection layers which we apply to tandem, triple, 4-terminal and series-parallel configurations. The thesis has been organized into five chapters. Chapter 1 introduces concepts required for the development of the thesis work including the optical model. Chapter 2 describes the optical optimization and experimental implementation of current-matched multi-junction devices using PTB7:PC71BM, including applications. In order to profit from the advantage of electrically separated devices, Chapter 3 evaluates different types of 4-terminal architectures using PTB7:PC71BM and PTB7-Th:PC71BM. In one of the architectures we establish a serial-connection between sub-cells while in other we leave the sub-cells completely independent. Chapter 4 theoretically proposes a novel monolithic architecture combining perovskites and CIGS which does not require current-matching. Finally, in Chapter 5, an in-depth study of the semi-transparent inner electrodes is given that include vacuum-based and solution-processed layers.La fotovoltaica de capa delgada engloba un grupo de tecnologías capaces de capturar la luz en tan sólo unos pocos nanómetros de espesor. Su bajo costo de manufactura, flexibilidad y bajo peso, hace a las capas delgadas candidatas ideales para la integración en edificios. En particular, las celdas orgánicas pueden proveer una transparencia de alta calidad similar a las ventanas convencionales irrealizable con tecnologías basadas en Silicio. Sin embargo, para la producción de electricidad a gran escala en donde la eficiencia es, tal vez, el factor determinante, existen nuevas tecnologías como las celdas solares de perovskita que pueden resultar más adecuadas. Al momento de escribir esta tesis, las eficiencias de celdas de perovskita de simple unión casi duplican la de las mejores celdas orgánicas de simple unión. Una limitante de ambas tecnologías, en especial de las celdas orgánicas y en menor medida de las perovskitas, es la baja movilidad de las cargas. Esta, junto a otras desventajas de los absorbentes orgánicos y perovskitas limita su espesor al rango de los 100 a los 130 nm, y entre los 500 a 600 nm, respectivamente. En resumen, el manejo de la luz debe constituir un ingrediente esencial para el diseño de los dispositivos, tal que se consiga un desempeño óptimo en la aplicación para la cual sean considerados. En esta tesis, con el fin de alcanzar un aprovechamiento óptimo de la luz y por ende aumentar el desempeño de las celdas solares de capa delgada, utilizamos dos enfoques. Por un lado, aumentamos el espesor total de material absorbente dentro del dispositivo sin incrementar el espesor de las capas actives individuales y por otro lado, combinamos absorbentes complementarios para cubrir una porción más amplia del espectro solar. Estos enfoques conllevan al doble reto de encontrar la distribución de campo electromagnético óptima dentro de una estructura compleja de multicapas con dos o más capas activas, junto a la implementación de una recolección o recombinación de cargas efectiva por parte de las capas intermedias encargadas de conectar dos subceldas adyacentes. En el caso de las celdas orgánicas, consideramos celdas de multiunión usando el mismo material activo para todas las subceldas. Para implementarlas, se realizan estructuras cuyas capas activas no excedan los 100 nm. También estudiamos configuraciones donde los materiales tienen absorciones complementarias usando perovskitas. En ambos casos, sobretodo en el primero, se requiere un método sistemático para optimizar el aprovechamiento de la luz. Para obtener las configuraciones óptimas empleamos una estrategia de integración inversa junto con un cálculo del campo eléctrico basado en el modelo de matriz de transferencia. Además, desarrollamos nuevas estrategias para optimizar la colección de cargas en las capas de interconexión de las subceldas aplicables a dispositivos tipo tandem, triple, 4-terminales y serie-paralelo.Universitat Politècnica de CatalunyaMartorell Pena, Jordi20172017-04-2420172017-10-02doctoral thesishttp://purl.org/coar/resource_type/c_db06VoRhttp://purl.org/coar/version/c_970fb48d4fbd8a85info:eu-repo/semantics/doctoralThesisapplication/pdfhttps://hdl.handle.net/2117/108231https://dx.doi.org/10.5821/dissertation-2117-108231reponame:UPCommons. Portal del coneixement obert de la UPCinstname:Universitat Politècnica de Catalunya (UPC)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2http://creativecommons.org/licenses/by-nc-sa/4.0/info:eu-repo/semantics/openAccessoai:upcommons.upc.edu:2117/1082312026-05-27T15:37:01Z |
| score |
15,300719 |