Dark Current - Voltage Characteristics and Lock-in Thermography Techniques as Diagnostic Tools for Monocrystalline Silicon Solar Cells

In this paper, a highly sensitive lock- in thermography system has been used, enabling the detection of periodic surface temperature oscillations below 10 mu K (r.m.s). Spatially resolved power loss images obtained by Lock-In Thermography (LIT) for a single crystalline silicon solar cell carried out. A significant difference is shown for the solar cell with shunts, while series resistance and charge carrier recombination cause only minor differences in the images. This system has been used to investigate edge leakage shunts currents in silicon solar cells of the construction n(1) pp(11) PESC Passivated Emitter Solar Cell (silicon wafers doped with Boron) after 4000 hrs of thermal stress at 400 K. The dark I-V characteristics of the solar cell, as a diagnostic tool, are studied and analysed. A decrease of the electrical parameters of the solar cell has been obtained after thermal stress.