Hot spotting and second breakdown effects on reverse I-V characteristics for mono-crystalline Si Photovoltaics

Author

Kim, Katherine A. ; Krein, Philip T.

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Illinois at Urbana-Champaign, Urbana, IL, USA

fYear

2013

fDate

15-19 Sept. 2013

Firstpage

1007

Lastpage

1014

Abstract

Hot spots are a common problem in photovoltaic (PV) panels that accelerate cell degradation and reduce system performance. Hot spots occur when a cell is reversed biased, sinks power, and heats the cell. At a certain threshold, the PV p-n junction goes into second breakdown and heats a small portion of the cell to very high temperatures. This study experimentally tests mono-crystalline Si cells as they hot spot at different power levels. Heating effects on the I-V characteristics during hot spotting and permanent changes after seven days of hour-long hot spot tests are observed and analyzed. I-V characteristics are significantly affected under second breakdown, which is observed when cells are reverse-biased above two times the rated maximum power level.

Keywords

electric breakdown; elemental semiconductors; solar cells; Si; hot spotting; monocrystalline silicon cells; monocrystalline silicon photovoltaics; reverse I-V characteristics; second breakdown; second breakdown effects; Acceleration; Degradation; Electric breakdown; Heating; Silicon; Temperature; Temperature measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Energy Conversion Congress and Exposition (ECCE), 2013 IEEE

Conference_Location

Denver, CO

Type

conf

DOI

10.1109/ECCE.2013.6646813

Filename

6646813