STUDY OF A THERMOPHOTOVOLTAIC CONVERTER.
Abstract
Components for a portable thermophotovoltaic converter were investigated experimentally and theoretically. Reflector-calorimeters were constructed for heat balance studies, and a first test of mounting procedures and techniques for cells in sets of twenty conducted. Individual nonreflecting cells (without interferencg coatings) were studied for efficiency as a function of incident radiation density. Cells were 5.5 - 6% efficient at corresponding illumination levels of 9 - 6 watts/sq cm and power output densities of 0.38 - 0.30 watts/sq cm. The transmission of intrinsic germanium wafers at wavelengths beyond the absorption edge was meassured under high optical injection conditions. No change in transmission was observed, although a change of even 1% could have been detected. Reflectance measurements were extended to analyze the individual multiple reflections, clearly observed in samples with wedge (following modifications of the reflectance goniometer). These studies aid in interpreting some of the reflectance profiles of samples showing local roughness. The series resistance of photovoltaic cells was analyzed. An approximate model (a simple, one-lump model), consisting of a constant current source in parallel with a diode and with a resistance in series whose value is equal to 0.4 of the calculated sheet resistance, describes the situation very well. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 07, 1964
- Accession Number
- AD0449713