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Advanced methods for modern solar cells:
Matching solar spectrum absorption and inorganic/organic cell materials for enhancement of cell efficiency and functioning time
Or Gindi; orgindy@gmail.com Dr. Peter Beker, Dr. Zeev Fradkin
Sami Shamoon College of Engineering, Ashdod, Israel.
The ongoing global energy crisis underscores the importance of transitioning towards renewable energy sources. Among the renewable energy forms, solar energy has decidedly carved out a significant role, owing to its extensive availability and eco-friendly nature. The energy derived from the Sun’s rays is as one of the most promising alternatives. However, the efficiency of solar photovoltaic )PV( systems is a complex subject influenced by several factors, such as solar radiation wavelengths, weather conditions, and materials. A salient issue is the decline in the PV module’s performance due to increased operating temperatures, which significantly impact the open circuit voltage. Historically, numerous solutions, like active cooling systems and passive radiators, have been posited to mitigate the thermal challenges inherent in solar energy harnessing. Yet, these solutions often entail their own set of challenges, related to cost, engineering integration, and infrastructural support. This research endeavours to present a passive solution for the management of the operating temperature of PV modules, focusing either on the utilization of optical filters to exclude undesirable infrared )IR( light or employing multilayered cells to harness the desirable spectrum of light. The value of this proposal arises from the fact that, when absorbed, the photons from the IR wavelengths often lack the energy required to exceed the cells’ bandgap, thereby merely contributing to heating the module and reducing its efficiency. The focal point of this study is the exploration of the potential of IR optical filters to curtail the adverse effects of temperature escalation in PV modules due to IR light absorption. The development of such filters would offer a cost-effective solution by enhancing the thermal efficiency of PV systems. Given that the IR wavelengths constitute about 30% of the Sun’s energy, harnessing this untapped energy resource would be most efficient. This development might also include the use of innovative materials, capable of converting IR radiation into electricity, without unnecessarily heating the standard PV cells. The effectiveness of an IR filter for mitigating temperature-induced power losses in silicon solar cell devices was investigated. Despite a 13% power drop due to reduced transparency, the use of the developed IR filter indeed produced higher efficiency over an extended period of time. The results of this research revealed a notable 3% increase in the fill factor and a temperature difference of 10-15°C. This outcome, although coupled with a power drop, still represents a substantial improvement when juxtaposed with previous comparable studies. The exigency now lies in the investigation of innovative materials and designs towards the development of an optimal filter that not only mitigates IR radiation but also harnesses the otherwise wasted IR energy into produced electricity. Moreover, this research introduces the concept of using organic solar cells as IR filters and proposes a cleaner fabrication method )physical vapor deposition, PVD(. By means of PVD, it was feasible to delve into the fabrication of organic solar cells utilizing polymers )PCPDTBT and fullerene PCBM(. A series of comprehensive experiments led to insights about the optimal
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