Investigation of Nanostructured Surfaces for Thermophotovoltaic Applications

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2021-9
Atak, Eslem Enis
Thermophotovoltaic (TPV) devices convert thermal radiation into electricity by using a thermal emitter and a photovoltaic (PV) cell. TPV systems can utilize variety of heat sources, which makes them suitable for harvesting waste heat. The downside of current TPV technology is its low efficiency due to the spectral mismatch between thermal emission of the emitter and the bandgap of the cell. In this thesis, the effect of nanostructures on radiative properties is studied in order to develop efficient TPV emitters and cells. Accordingly, metal-insulator-metal (MIM) nanostructured TPV emitters to match GaSb and Si cells were designed and optimized in order to achieve high power output and efficiency, by using finite-difference time-domain (FDTD) and particle swarm optimization (PSO) methods. In addition, nanostructured Si cells were developed to increase useful absorption without cell heating, by FDTD and parameter sweep methods. At 1700 K, W-SiO2-W emitter showed an efficiency of 22.73% and power output of 3.622 W∙cm-2, which is 177% more efficient and produces 9.7% more power than SiC emitter paired with GaSb. At 2000 K, Ta-HfO2-Ta emitter demonstrated an efficiency of 27.91% and power output of 4.755 W∙cm-2, which is 53.3% more efficient while producing 87.4% more power than Yb2O3 emitter paired with Si. In nanostructured Si cells, useful radiation increased by 30.4% while limiting thermalization increase to 24.4%, compared to flat Si cell, when illuminated by a blackbody at 2000 K. The results of this work are expected to shed a light onto the potential of developing high efficiency TPV systems.

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Citation Formats
E. E. Atak, “Investigation of Nanostructured Surfaces for Thermophotovoltaic Applications,” M.S. - Master of Science, Middle East Technical University, 2021.