Evaluation of Inline High-Intensity Illumination Treatments against LeTID

High-intensity illumination treatments are a versatile method to reduce the performance loss of solar cells due to LeTID since they can be applied at any point of time between cell fabrication and module assembly. We evaluate the potential of these treatments using a true inline treatment tool and commercially available PERC solar cells. To test the stability of cell performance after the treatments, the cells were exposed to 0.15 suns and 75 °C at open circuit. These conditions are close to a recent testing standard suggestion and allow estimating the cell stability over the typical operating lifetime of solar modules. The results show that there is a window of process parameters which improves the stability of solar cell efficiency without compromising the efficiency immediately after the treatment, i.e. before the stability test. The treatments result in an estimated gain of ~ 3 % in the amount of energy produced by the cells during the operating lifetime of a solar module, corresponding to a reduction of LeTID-related energy yield losses by up to ~ 50 %. Importantly, this gain is achievable with belt speeds compatible with high throughput inline processing.