Express – Analysis of Local Current Density Distribution Over the Area of PV Cells Using Thermovision Systems
Abstract
The current density distribution over the area of photovoltaic cell is an important characteristic for at least two reasons. The first one - the homogeneity of the current density distribution characterizes the quality of solar cell production and second - the heterogeneity of the photocurrent distribution leads to local overheating of the solar cell and consequently decrease in its lifespan. The paper describes the methodology and experimental results of current density distribution research over the area of PV cell by thermovision-thermographic method. Silicon solar cells of different design where researched. Over the area of investigated samples, the spots of local Joule overheating are observed due to higher current density in these localities. The study of these spots by Laser Beam Induced Current (LBIC) method showed the presence of leakage current through p-n junction.
Keywords
Photovoltaic cell, Thermal imaging system, Infrared (ir) region of spectrum, Forward- and back- biased diode, Local leakage current, Vertical multijunction solar cells, Ir thermovision picture