Matching Items (6)
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- All Subjects: solar
- Creators: Bertoni, Mariana
Description
A hybrid PV/T module was built, consisting of a thermal liquid heating system and a photovoltaic module system that combine in a hybrid format. This report will discuss the work on the project from Fall 2012 to Spring 2013 and the extended section on the economics for the Honors Thesis. Three stages of experiments were completed. Stage 1 showed our project was functional as we were able to verify our panel produced electricity and increased the temperature of water flowing in the system by 0.65°C. Stage 2 testing included “gluing” the flow system to the back of the panel resulting in an average increase of 4.76°C in the temperature of the water in the system. Stage 3 testing included adding insulating foam to the module which resulted in increasing the average temperature of the water in our flow system by 6.95°C. The economic calculations show the expected energy cost savings for Arizona residents.
ContributorsHaines, Brent Robert (Author) / Roedel, Ronald (Thesis director) / Aberle, James (Committee member) / Rauch, Dawson (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2013-05
Description
A high voltage plasma arc can be created and sustained in air by subjecting the gases to an electric field with high voltage potential, causing ionization. The internal energy of the ionized gases can be transferred to corresponding pressure waves when the matter involved switches between the gaseous and plasma states. By pulse-width modulating a transformer driving signal, the transfer of internal electrical energy to resonating pressure waves may be controlled. Audio wave input to the driver signal can then be modulated into the carrier wave and be used to determine the width of each pulse in the plasma, thus reconstructing the audio signal as pressure, or sound waves, as the plasma arc switches on and off. The result will be the audio waveform resonating out of the plasma arc as audible sound, and thus creating a plasma loudspeaker. Theory of operation was tested through construction of a plasma arc speaker, and resultant audio playback was analyzed. This analysis confirmed accurate reproduction of audio signal in audible sound.
ContributorsBoehringer, Brian Thomas (Author) / Roedel, Ronald (Thesis director) / Huffman, James (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2014-05
Description
Layers of intrinsic hydrogenated amorphous silicon and amorphous silicon carbide
were prepared on a polished, intrinsic crystalline silicon substrate via plasma-enhanced chemical vapor deposition to simulate heterojunction device relevant stacks of various materials. The minority carrier lifetime, optical band gap and FTIR spectra were observed at incremental stages of thermal annealing. By observing the changes in the lifetimes the sample structure responsible for the most thermally robust surface passivation could be determined. These results were correlated to the optical band gap and the position and relative area of peaks in the FTIR spectra related to to silicon-hydrogen bonds in the layers. It was found that due to an increased presence of hydrogen bonded to silicon at voids within the passivating layer, hydrogenated amorphous silicon carbide at the interface of the substrate coupled with a hydrogenated amorphous silicon top layer provides better passivation after high temperature annealing than other device structures.
were prepared on a polished, intrinsic crystalline silicon substrate via plasma-enhanced chemical vapor deposition to simulate heterojunction device relevant stacks of various materials. The minority carrier lifetime, optical band gap and FTIR spectra were observed at incremental stages of thermal annealing. By observing the changes in the lifetimes the sample structure responsible for the most thermally robust surface passivation could be determined. These results were correlated to the optical band gap and the position and relative area of peaks in the FTIR spectra related to to silicon-hydrogen bonds in the layers. It was found that due to an increased presence of hydrogen bonded to silicon at voids within the passivating layer, hydrogenated amorphous silicon carbide at the interface of the substrate coupled with a hydrogenated amorphous silicon top layer provides better passivation after high temperature annealing than other device structures.
ContributorsJackson, Alec James (Author) / Holman, Zachary (Thesis advisor) / Bertoni, Mariana (Committee member) / Kozicki, Michael (Committee member) / Arizona State University (Publisher)
Created2016
Description
The project described here is a solar powered intrusion detection system consisting of three modules: a battery recharging circuit, a laser emitter and photodetector pair, and a Wi- Fi connectivity board. Over the preceding seven months, great care has been taken for the design and construction of this system. The first three months were spent researching and selecting suitable IC's and external components (e.g. solar panel, batteries, etc.). Then, the next couple of months were spent ordering specific materials and equipment for the construction of our prototype. Finally, the last two months were used to build a working prototype, with a substantial amount of time used for perfecting our system's packaging and operation. This report will consist of a detailed discussion of our team's research, design activities, prototype implementation, final budget, and final schedule. Technical discussion of the concepts behind our design will assist with understanding the design activities and prototype implementation sections that will follow. Due to the generous funding of the group from the Barrett Honors College, our overall budget available for the project was $1600. Of that amount, only $334.51 was spent on the actual system components, with $829.42 being spent on the equipment and materials needed for the testing and construction of the prototype. As far as the schedule goes, we are essentially done with the project. The only tasks left to finish are a successful defense of the project at the oral presentation on Friday, 29 March 2013, followed by a successful demo on 26 April 2013.
ContributorsTroyer, Nicole L. (Co-author) / Shtayer, Idan (Co-author) / Guise, Chris (Co-author) / Kozicki, Michael (Thesis director) / Roedel, Ronald (Committee member) / Goodnick, Stephen (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2013-05
Description
The metallization and interconnection of Si photovoltaic (PV) devices are among some of the most critically important aspects to ensure the PV cells and modules are cost-effective, highly-efficient, and robust through environmental stresses. The aim of this work is to contribute to the development of these innovations to move them closer to commercialization.Shingled PV modules and laser-welded foil-interconnected modules present an alternative to traditional soldered ribbons that can improve module power densities in a cost-effective manner. These two interconnection methods present new technical challenges for the PV industry. This work presents x-ray imaging methods to aid in the process-optimization of the application and curing of the adhesive material used in shingled modules. Further, detailed characterization of laser welds, their adhesion, and their effect on module performances is conducted. A strong correlation is found between the laser-weld adhesion and the modules’ durability through thermocycling. A minimum laser weld adhesion of 0.8 mJ is recommended to ensure a robust interconnection is formed.
Detailed characterization and modelling are demonstrated on a 21% efficient double-sided tunnel-oxide passivating contact (DS-TOPCon) cell. This technology uses a novel approach that uses the front-metal grid to etch-away the parasitically-absorbing poly-Si material everywhere except for underneath the grid fingers. The modelling yielded a match to the experimental device within 0.06% absolute of its efficiency. This DS-TOPCon device could be improved to a 23.45%-efficient device by improving the optical performance, n-type contact resistivity, and grid finger aspect ratio.
Finally, a modelling approach is explored for simulating Si thermophotovoltaic (TPV) devices. Experimentally fabricated diffused-junction devices are used to validate the optical and electrical aspects of the model. A peak TPV efficiency of 6.8% is predicted for the fabricated devices, but a pathway to 32.5% is explained by reducing the parasitic absorption of the contacts and reducing the wafer thickness. Additionally, the DS-TOPCon technology shows the potential for a 33.7% efficient TPV device.
ContributorsHartweg, Barry (Author) / Holman, Zachary (Thesis advisor) / Chan, Candace (Committee member) / Bertoni, Mariana (Committee member) / Yu, Zhengshan (Committee member) / Arizona State University (Publisher)
Created2023
Description
The investigation into wide band gap semiconductors for use in tandem solar cells has become an increasingly more researched area with many new absorbers outlining the landscape. Pairing silicon with another cheap wide band gap semiconductor absorber can generate more efficient solar cell, which could continue to drive up the energy output from solar. One such recently researched wide band gap absorber is ZnSnN2. ZnSnN2 proves too difficult to form under most conditions, but has the necessary band gap to make it a potential earth abundant solar absorber. The deposition process for ZnSnN2 is usually conducted with Zn and Sn metal targets while flowing N2 gas. Due to restrictions with chamber depositions, instead ZnO and SnO2 targets were sputtered with N2 gas to attempt to form separate zinc and tin oxynitrides as an initial single target study prior to future combinatorial studies. The electrical and optical properties and crystal structure of these thin films were analyzed to determine the nitrogen incorporation in the thin films through X-ray diffraction, UV-Vis spectrophotometry, and 4-point probe measurements. The SnO2 thin films showed a clear response in the absorption coefficient leading but showed no observable XRD peak shift. Thus, it is unlikely that substantial amounts of nitrogen were incorporated into SnO¬2. ZnO showed a clear response increase in conductivity with N2 with an additional shift in the XRD peak at 300 °C and potential secondary phase peak. Nitrogen incorporation was achieved with fair amounts of certainty for the ZnO thin films.
ContributorsTheut, Nicholas C (Author) / Bertoni, Mariana (Thesis director) / Holman, Zachary (Committee member) / Materials Science and Engineering Program (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05