Here, we demonstrate the effectiveness of illuminated annealing using high-intensity light to improve the efficiency of industrial n-type silicon heterojunction (SHJ) solar cells. The application of high intensity laser light during annealing at 200 °C led to efficiency improvements as large as 0.7% <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">abs</sub> and final efficiencies as high as 24.5%. This was demonstrated on industrial SHJ solar cells from five different manufacturers, indicating the robust application of this technique. We show that the annealing process with high-intensity light leads to significant efficiency enhancements compared to previous observations using light soaking under 1-sun conditions, meaning the process can be completed in 30 s, rather than hours. The observed enhancements were related to increased V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OC</sub> and fill factor. If this approach can be tailored to time scales amenable with mass production, the associated efficiency enhancements could drive reductions in the levelized cost of electricity for SHJ solar cells, making them more competitive in the face of existing technologies.