Mechanism of thermal runaway in solar cells

Abstract

Abstract To clarify the mechanism of thermal runaway in solar cells, our study included experiments and simulations that focused on changes in the size of the shunt spot where thermal runaway occurs. Our analysis suggests that the rapid temperature increase of the shunt spot leading to failure is caused by the positive feedback of increased backflow current, increased heat generation, and reduced shunt spot size (i.e. increased combined thermal resistance between the shunt spot and normal cell area). The thermal runaway tolerance can be improved by designing solar cells with negative feedback that prevents positive feedback from progressing.