Title :
Nonuniform power generation in polycrystalline thin film photovoltaics
Author :
Karpov, V.G. ; Harju, R. ; Dorer, G.
Author_Institution :
First Solar, LLC, Perrysburg, OH, USA
Abstract :
We consider effects of nonuniformities on thin film photovoltaics where microscopic parameters vary between different local regions. Our experimental data on polycrystalline CdTe/CdS PV cells reveal nonuniformities of different space scales. A related theoretical problem of macroscopic parameters in randomly nonuniform thin film PV cell is solved in the effective medium approximation. The effective open circuit voltage and correlation length in the cell are calculated. The theory predicts hot spots caused by local currents circulating in the system under open circuit conditions
Keywords :
II-VI semiconductors; cadmium compounds; semiconductor thin films; solar cells; CdTe-CdS; correlation length; effective medium approximation; hot spots prediction; local currents circulation; macroscopic parameters; microscopic parameters; nonuniform power generation; nonuniformities; open circuit conditions; open circuit voltage; polycrystalline CdTe/CdS PV cells; polycrystalline thin film photovoltaics; randomly nonuniform thin film PV cell; Electric potential; Electric resistance; Electron beams; Grain boundaries; Photovoltaic cells; Power generation; Scanning electron microscopy; Thin film circuits; Transistors; Voltage;
Conference_Titel :
Photovoltaic Specialists Conference, 2000. Conference Record of the Twenty-Eighth IEEE
Conference_Location :
Anchorage, AK
Print_ISBN :
0-7803-5772-8
DOI :
10.1109/PVSC.2000.915895
