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31st European Photovoltaic Solar Energy Conference and Exhibition; 55-58, Thermophotovoltaic (TPV) technologies used in conjunction with present infrastructure can lead to increased energy output by reclaiming the heat lost during production processes. To maximize the efficiency of these sources, the conversion efficiency of the TPV system needs to be optimized. Metamaterials provide an excellent medium for the creation of selective emitters. Such emitters tailor the incident light spectrum to the band gap of the diode in question, offering the potential to reduce diode heating and increase efficiency. We have created such devices at a wide range of wavelengths to observe the performance of various sized nanostructures at high temperatures. Usage of conducting metals such as platinum and iridium makes the emitters able to withstand the high temperatures required to create ideal spectra for III-V cells. Simulations from CST Microwave Studio were used in the design process and testing of the emitters included ellipsometer absorption measurements and emission testing using a high temperature blackbody source.

31st European Photovoltaic Solar Energy Conference and Exhibition; 1474-1477, Under ultra-high solar concentration, drastic efficiency drops are attributed to a deteriorating fill factor and additional thermal effects. The effects of ultra-high solar concentration on other fundamental electrical properties, such as open-circuit voltage, have yet to be explored in detail. In this work, we discuss our theoretical examination of semiconductor performance under ultra-high irradiance. Using advanced numerical analysis techniques and the finite-element library deal.II, we develop a computational model to simultaneously solve the carrier continuity equations and Poisson’s equation for optically generated charge carriers and the resulting electric potential as functions of space and time. We use this model to analyze VOC in both dynamic and quasi-steady state conditions. Ultimately, we characterize the relationship between VOC and increasing solar concentration.

29th European Photovoltaic Solar Energy Conference and Exhibition; 280-283, Thermophotovoltaics has recently garnered significant interest in the field of renewable energy. This is due to their versatility and promise to achieve efficiencies well beyond the Shockeley-Queisser Limit that dictates the performance of photovoltaics [1,2]. Thermophotovoltaics generate electricity from heat converted into infrared photons. In this study, we focus our attention to Ga1-xTlxP, a tertiary compound with the potential of having a lower bandgap with increasing Thallium (Tl) content. TlP belongs to a group of materials known as semi-metals and possesses an optical bandgap below zero [3]: This implies that the material bandgap can theoretically change from 2.26 eV (x=0) to -0.27 eV (x=1). Presented in this study are the implications such a band structure change could have on the associated properties such as the optical bandgap and lattice constant of GaTlP with varying Tl content. The versatility in Tl content allows for a number of candidate substrates including GaAs, Ge, and InP.

29th European Photovoltaic Solar Energy Conference and Exhibition; 334-337, The efficiency of existing energy sources can be increased through the application of thermophotovoltaic (TPV) technologies, which would reclaim lost heat and turn it back into usable electricity. In order to maximize the efficiency of these sources, the conversion efficiency of the TPV system needs to be optimized. Using metamaterials, we have created selective emitters that tailor the incident light spectrum to the band gap of specific diodes, offering the potential to reduce diode heating and increase efficiency. Usage of metals such as platinum and tungsten makes the emitters able to withstand the high temperatures required to create ideal spectra for III-V cells. Simulations from CST Microwave Studio were used in the design process.

28th European Photovoltaic Solar Energy Conference and Exhibition; 269-273, Applying thermophotovoltaics (TPV) to present energy production technologies allows us to increase energy output while utilizing existing infrastructure by reclaiming the heat lost during the production process. In order to maximize the efficiency of these sources, the conversion efficiency of the TPV system needs to be optimized. Using metamaterials, we have created selective emitters that tailor the incident light spectrum to the band gap of specific diodes, offering the potential to reduce diode heating and increase efficiency. Usage of metals such as platinum and molybdenum makes the emitters able to withstand the high temperatures required to create ideal spectra for III-V cells. Simulations from CST Microwave Studio were used in the design process and testing of the emitters includes heat tests and SEM analysis.

28th European Photovoltaic Solar Energy Conference and Exhibition; 365-368, Thermophotovoltaic (TPV) cells are semiconductor devices which convert radiated heat directly into electricity. This work investigates extending the operational wavelength of such devices into the long-wavelength infrared regime. Specifically, this work explores the use a barrier layer inserted into a p-n junction to suppress recombination pathways. Dark current simulations have been performed comparing a heterojunction barrier case with a typical p-n junction. Doping levels were varied to adjust the size of the space charge region of the junction and simulate the effect of different barrier widths within the depletion region.