Local current-voltage curves measured thermally (LIVT): A new technique of characterizing PV cells

Abstract

Local current-voltage characteristics measured thermally (LIVT) is a non-destructive technique based on measuring the bias dependence of the local temperature of a small sample area in the ac mode. It is an important supplement to light beam induced current (LBIC), electron beam induced current (EBIC) and Dynamic Precision Contact Thermography (DPCT) techniques allowing to study the nature of the current at a given point on the cell surface. Presented experimental results comprise LIVTs of natural inhomogeneities in multicrystalline silicon solar cells, artificial defects in monocrystalline cells (mechanically damaged regions), as well as LIVTs of several test structures. LIVT data generally confirm existing theories for different current natures. A related technique for n-factor mapping is also presented.