Title :
New upper efficiency limits for semiconductor solar cells
Author :
Werner, Jurgen H. ; Brendel, Rolf ; Oueisser, H.J.
Author_Institution :
Max-Planck-Inst. fur Festkorperforschung, Stuttgart, Germany
Abstract :
Quantum efficiency measurements showed that more than one electron/hole pair per absorbed photon can be created in a solar cell. Theoretical consideration of this effect leads to new upper radiative efficiency limits for photovoltaic energy conversion. More than 43% efficiency are theoretically possible for cells which are illuminated by the Sun´s unconcentrated black body radiation. For sunlight of full concentration, the new limit is above 85%. These values are theoretically possible with a single semiconductor which makes efficient use of carrier multiplication. The theoretical description of radiative recombination in a cell with carrier multiplication leads us also to a novel mathematical description of the saturation current density
Keywords :
carrier density; electron-hole recombination; minority carriers; semiconductor device models; solar cells; absorbed photon; carrier multiplication; electron/hole pair; photovoltaic energy conversion; quantum efficiency measurements; radiative efficiency limits; radiative recombination; saturation current density; semiconductor solar cells; unconcentrated black body radiation; upper efficiency limits; Charge carrier processes; Current density; Hot carrier effects; Lighting; Photovoltaic cells; Photovoltaic systems; Radiative recombination; Short circuit currents; Sun; Temperature;
Conference_Titel :
Photovoltaic Energy Conversion, 1994., Conference Record of the Twenty Fourth. IEEE Photovoltaic Specialists Conference - 1994, 1994 IEEE First World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
0-7803-1460-3
DOI :
10.1109/WCPEC.1994.520555
