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Study of photovoltaic nanostructures using microscopy methods
Hertl, Vít ; Valenta,, Jan (oponent) ; Fejfar, Antonín (vedoucí práce)
At the beginning this master's thesis lays brief fundamentals to physics of solar cells, where the main processes influencing the sunlight-to-electrical energy conversion efficiency are mentioned. After that the literature research is presented giving overview of photovoltaic nanostructures (e.g. nanowires, nanocrystals), which allow to increase the efficiency of the solar cells when implemented. Further, the experimental characterization techniques of the photovoltaic nanostructures are presented, focused especially at correlative SEM and AFM, conductive AFM, EBIC and microscopical electroluminescence measurements. In the experimental part the results obtained from the following samples are presented: Microcrystalline silicon structures, the sample of interdigitated back-contact Si heterojunction solar cell (IBC-SHJ from project NextBase) and V-pits in the sample with InGaN/GaN quantum wells. Electroluminescence measurement was performed on the III-V semiconductors (InGaP, GaAs). Some characteristics of the III-V tandem solar cells that are hard to obtain by ordinary methods were computed from electroluminescence. Finally, the EBIC and microscopical electroluminescence measurements were compared for IBC-SHJ solar cell. Experiments on microcrystalline silicon revealed division of two current routes; through the AFM tip and into the sample with the electron beam serving as the current source.
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Multiband solar sensors data acquisition and cloud processing
Hertl, Vít ; Kaczmarczyk, Václav (oponent) ; Holek, Radovan (vedoucí práce)
This master's thesis builds upon the foundations laid in the same-titled semestral thesis. At the beginning the fundamental properties of sunlight that are needed for understanding of the performance ratio computation are briefly mentioned. After that the solar sensors developed in ReRa Solutions which provided the solar irradiance measured data are described. In the following literary research part the alternatives to unreliable sensor's Wi-Fi connection are compared and the most suitable connection technology is concluded to be LoRa. In the practical part the design and development process of a single page application solution is described in detail. The application allows the sensors to log measured data into the database and is able to retrieve and display them back to the user in an intelligible form. The application benefits from modern programming languages and frameworks (e.g. Kotlin, Spring, TypeScript, React, Material-UI). The database model was designed with respect to real-world scenario introducing the monitored area concept allowing extensive configuration possibilities. Then the model was transferred into the database in the form of programmable entities. Further, the client-server communication via REST API allowing role-based authentication was implemented. The application GUI allows to configure the environment according to user needs and renders interactive graphs with sensor measured data. The application was deployed in Google Cloud with a separate database.
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Příprava a testování SNOM sond se speciálními vlastnostmi
Hertl, Vít ; Kvapil, Michal (oponent) ; Spousta, Jiří (vedoucí práce)
Tato bakalářská práce je zaměřena na přípravu funkčních sond z konvenčního dutého optického vlákna a jejich testování při měření na aparatuře SNOM. Dále se zde studují speciální vlastnosti těchto sond především jejich využití jako "nanoGIS". Předpokládá se vyřešení hlavních problémů spojených s přípravou sondy jako je například leptání vlákna zevnitř.
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Study of photovoltaic nanostructures using microscopy methods
Hertl, Vít ; Valenta,, Jan (oponent) ; Fejfar, Antonín (vedoucí práce)
At the beginning this master's thesis lays brief fundamentals to physics of solar cells, where the main processes influencing the sunlight-to-electrical energy conversion efficiency are mentioned. After that the literature research is presented giving overview of photovoltaic nanostructures (e.g. nanowires, nanocrystals), which allow to increase the efficiency of the solar cells when implemented. Further, the experimental characterization techniques of the photovoltaic nanostructures are presented, focused especially at correlative SEM and AFM, conductive AFM, EBIC and microscopical electroluminescence measurements. In the experimental part the results obtained from the following samples are presented: Microcrystalline silicon structures, the sample of interdigitated back-contact Si heterojunction solar cell (IBC-SHJ from project NextBase) and V-pits in the sample with InGaN/GaN quantum wells. Electroluminescence measurement was performed on the III-V semiconductors (InGaP, GaAs). Some characteristics of the III-V tandem solar cells that are hard to obtain by ordinary methods were computed from electroluminescence. Finally, the EBIC and microscopical electroluminescence measurements were compared for IBC-SHJ solar cell. Experiments on microcrystalline silicon revealed division of two current routes; through the AFM tip and into the sample with the electron beam serving as the current source.
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Multiband solar sensors data acquisition and cloud processing
Hertl, Vít ; Kaczmarczyk, Václav (oponent) ; Holek, Radovan (vedoucí práce)
This master's thesis builds upon the foundations laid in the same-titled semestral thesis. At the beginning the fundamental properties of sunlight that are needed for understanding of the performance ratio computation are briefly mentioned. After that the solar sensors developed in ReRa Solutions which provided the solar irradiance measured data are described. In the following literary research part the alternatives to unreliable sensor's Wi-Fi connection are compared and the most suitable connection technology is concluded to be LoRa. In the practical part the design and development process of a single page application solution is described in detail. The application allows the sensors to log measured data into the database and is able to retrieve and display them back to the user in an intelligible form. The application benefits from modern programming languages and frameworks (e.g. Kotlin, Spring, TypeScript, React, Material-UI). The database model was designed with respect to real-world scenario introducing the monitored area concept allowing extensive configuration possibilities. Then the model was transferred into the database in the form of programmable entities. Further, the client-server communication via REST API allowing role-based authentication was implemented. The application GUI allows to configure the environment according to user needs and renders interactive graphs with sensor measured data. The application was deployed in Google Cloud with a separate database.
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Příprava a testování SNOM sond se speciálními vlastnostmi
Hertl, Vít ; Kvapil, Michal (oponent) ; Spousta, Jiří (vedoucí práce)
Tato bakalářská práce je zaměřena na přípravu funkčních sond z konvenčního dutého optického vlákna a jejich testování při měření na aparatuře SNOM. Dále se zde studují speciální vlastnosti těchto sond především jejich využití jako "nanoGIS". Předpokládá se vyřešení hlavních problémů spojených s přípravou sondy jako je například leptání vlákna zevnitř.
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