LBIC: Seeing solar potential

• Digital imagery with laser lighting has been utilized to quantify a solar cell's performance for a while through a procedure called light beam induced current (LBIC) mapping. But, because of the serial nature of image processing, it has not been easy to do fast. Danish start-up InfinityPV states it has used a method which can expedite the LBIC rate by over 10 million times.

To detect PV defects and efficiency variations, laser beam lighting have been employed on solar cells using electronic imaging in a procedure known as light (or laser) beam induced current (LBIC) mapping to determine the performance or power conversion efficiency of a solar panel. With LBIC, there's a direct correspondence between the photovoltaic function in every pixel area of the solar cell and of the image, light is centered on each individual area, and the electric reaction is measured. The information contained in this LBIC picture is absolute and can even offer the external quantum efficiency (EQE) in every pixel - although the serial process of this technique suggests that rate is inherently slower. LBIC mapping has only been helpful for imaging little square millimeter-sized single junctions and on account of the sequential nature of image creation, large modules and panels are impossible to image in a quick industrial procedure. Until today, according to startup InfinityPV.

InfinityPV has committed considerable efforts toward inventing optical methods that enable rapid scan across the surface of a solar panel using quick low noise amplification of the photovoltaic signal.

The achievable image rates of a classical LBIC system with 100 micron resolution which use lock-in amplification with an integration time of 100 milliseconds per pixel may image one square centimeter (10,000 pixels) in 16 minutes. And a standard photovoltaic panel measuring 1 square meter would be 100,000,000 pixels and take 115 days.