Photovoltaic devices (PV) or more commonly “solar cells” are analyzed using LBIC/LBIV (Light Beam Induced Current/Voltage) PL (Photoluminescence) and EL (Electroluminescence) as well as INSB thermal Methods. This paper will show the advantages and pitfalls of the techniques as well as a novel way to perform EL imaging without a dark box and thermal imaging through glass panels.

The carrier collection properties of polycrystalline Si (poly-Si) thin film solar cells on glass with interdigitated mesa structure have been locally analysed with Infrared Light Beam Induced Current (IR-LBIC) and compared to LBIC measurements using visible light. The low absorption of IR light leads to a low current level when the light is coupled vertically into the active volume. An enhanced carrier collection has been detected at the corners of the mesa because the etch allows to couple the light horizontally into the solar cell, This investigation shows that IR-LBIC is sensitive to light trapping structures in silicon based thin film solar cells.

In this contribution the use of electroluminescence imaging, bias-dependent lock-in thermography, special dark and illuminated lock-in thermography techniques, and electron microscopy techniques is demonstrated for investigating the physical mechanism of breakdown in multicrystalline silicon solar cells. Two dominant breakdown mechanisms are identified, which are breakdown at recombination-active crystal defects, showing a relatively soft breakdown, and avalanche breakdown at dislocation-induced etch pits, which occurs very steep (hard breakdown) and dominates in our cells at high reverse bias.

Although crystalline silicon PV technology has been in use for more than 30 years, PV has remained a "cottage industry" until the recent expansion. This paper provides an introduction to the issues of reliability in the photovoltaic (PV) field, and the work the Department of Energy's Solar Energy Technologies Program is focused on to address these issues. In particular, the works of the Reliability Programs at both Sandia National Laboratories and the National Renewable Energy Laboratory are reviewed with several examples of results included and sited. Expanding reliability assessment and failure analysis techniques for components and systems can enhance the reliability of PV systems, which is necessary for large-scale deployment of PV as a power generation source.