Thin Film Narrow Bandgap InGaAs TPV Cells
Start Date
8-11-2017 1:30 PM
End Date
8-11-2017 5:30 PM
Abstract
Narrow-bandgap InGaAs thermophotovoltaic (TPV) cells grown on InP substrates can convert heat energy into electrical energy from commonly found fuels such as natural gas or propane. This is a great alternative in remote off-grid places where there is not very much sun exposure for solar cells. The problem is that TPV converters must be placed very close to the thermal source which can have temperatures between 900ºC and 1500ºC. Hence, the heat generated in the photocell must be removed as the operating temperature of the cell must remain below 80ºC for maximum efficiency. Therefore, we have isolated the InGaAs cell from the InP growth substrate and transfer it to a CVD diamond heat spreader to eliminate the substrate thermal resistance and remove the heat from the cells more efficiently. In addition to stay cooler, the thin film InGaAs are expected to outperform the cells with the growth substrate intact because the metal back-contact of the thin film cells acts as an optical mirror that reflects unabsorbed photons back into the cell increasing their optical path and their chance to be reabsorbed. The thick solar cells don’t have this effect because photons escape into the substrate. The process developed to achieve freestanding TPV cells and the electrical characterization of such cells will be presented in this poster.
Thin Film Narrow Bandgap InGaAs TPV Cells
Narrow-bandgap InGaAs thermophotovoltaic (TPV) cells grown on InP substrates can convert heat energy into electrical energy from commonly found fuels such as natural gas or propane. This is a great alternative in remote off-grid places where there is not very much sun exposure for solar cells. The problem is that TPV converters must be placed very close to the thermal source which can have temperatures between 900ºC and 1500ºC. Hence, the heat generated in the photocell must be removed as the operating temperature of the cell must remain below 80ºC for maximum efficiency. Therefore, we have isolated the InGaAs cell from the InP growth substrate and transfer it to a CVD diamond heat spreader to eliminate the substrate thermal resistance and remove the heat from the cells more efficiently. In addition to stay cooler, the thin film InGaAs are expected to outperform the cells with the growth substrate intact because the metal back-contact of the thin film cells acts as an optical mirror that reflects unabsorbed photons back into the cell increasing their optical path and their chance to be reabsorbed. The thick solar cells don’t have this effect because photons escape into the substrate. The process developed to achieve freestanding TPV cells and the electrical characterization of such cells will be presented in this poster.
