The spectral directional emissivity of photovoltaic surfaces

authored by: D. Labuhn, S. Kabelac
Abstract: Photovoltaic solar cells are used for the direct conversion of solar radiation to electric power. To evaluate the efficiency of this energy conversion process, all in- and outgoing fluxes in the thermodynamic balance equations for energy and entropy must be known. The spatial and spectral distribution of radiation energy intensities must be known to calculate the radiation energy fluxes. To calculate the entropy fluxes, additional information on the coherence properties of the radiation field is essential. This information is expressed by the degree of polarization. First results of measurements of the optical properties of a solar cell are presented. The calculation procedure to obtain the outgoing energy and entropy fluxes is described. The experimental apparatus introduced in this paper yields the spectral directional emissivity by comparing the sample radiation with the radiation from an isothermal cavity. The degree of polarization of the emitted radiation is determined by a retarder/polarizer set within the apparatus. Both quantities are measured in the infrared region for wavelengths between 4.0 and 20.0 μm.
External Organisation(s): Helmut Schmidt University
OHB System AG
Type: Article
Journal: International Journal of Thermophysics
Volume: 22
Pages: 1577-1592
No. of pages: 16
ISSN: 0195-928X
Publication date: 09.2001
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Condensed Matter Physics
Sustainable Development Goals: SDG 7 - Affordable and Clean Energy
Electronic version(s): https://doi.org/10.1023/A:1012817726103 (Access: Closed)