shunts diode breakdown and high reverse currents in multicrystalline silicon solar cells

• DOI: 10.4229/24theupvsec2009-2dv.1.11
• Publication Date: 2009-01-01
• Authors: M. Wagner; B. Gründig-Wendrock; P. Palinginis; C. Knopf
• Keywords: Mono- and Multicrystalline Silicon Materials and Cells; 02 engineering and technology; 0210 nano-technology; Wafer-based Silicon Solar Cells and Materials Technology; 7. Clean energy

24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 2028-2031<br/>Dark reverse IV-characteristics of multicrystalline silicon solar cells may have several different shapes depending on base material properties, cell process parameters, as well as their mutual interplay. All IV-curves have in common that at some cell specific reverse voltage high currents can be conducted. If this occurs at comparably low voltages, reverse currents may destroy the module under unfavorable operating conditions. Typically, high reverse currents are associated with (ohmic) shunts. However, there is another physical mechanism which results in such currents: regular diode breakdown. In multicrystalline silicon solar cells, the voltage at which this breakdown occurs is mainly governed by the resistivity of the base material. When the base resistivity is too low, high reverse currents under typical module operating conditions are possible even when no shunt is present.<br/>