CHARACTERISATION OF CRYSTALLINE SILICON SOLAR CELLS AND PHOTOVOLTAIC MODULES USING LUMINESCENCE IMAGING

Abstract

Luminescence imaging presents a non-destructive rapid method for in-depth characterisation of photovoltaic (PV) devices. This thesis investigates and develops methods to extract parameters (such as contact resistance, series resistance and module interconnect resistance) and their associated power losses via electroluminescence (EL) and photoluminescence (PL) imaging. At the solar cell level, a contactless method to determine contact resistance via localized-area photoinjection is developed and shown to be extendable to PV modules. At the PV module level, an EL imaging method is developed to extract resistive losses associated with cell-to-cell interconnection, without having to conduct prior I-V measurements. Using an EL analysis routine developed in this work, the series resistance and dark saturation current density of individual cells within a PV module can be estimated, along with their fill factor and efficiency, and that of the entire PV module, thus enabling an in-depth diagnosis of their performance.