Principle
Light-Induced Annealing (LIA): There are a large number of interface states (Si dangling bonds) at the interface of α-Si:H/c-Si. Studies have found that heating and annealing the structure under illumination conditions can effectively reduce the interface state (Si dangling bonds) density and interface recombination, thus improving the passivation effect of amorphous silicon (A-Si). This phenomenon is called light-induced annealing (LIA). In the HJT cell structure, there is an α-Si:H/c-Si interface; the HJT cell is heated and annealed under illumination, and the conversion efficiency of the cell is found to increase significantly, which is mainly reflected in the increase of Voc and FF.
Process Introduction
Laser LIA technology: HJT cell is irradiated by ultra-high power laser, and a large number of photo-induced cassettes are generated to change the valence state of hydrogen in α-Si:H, which reduces the interface recombination of α-Si:H/c-Si, thus increasing the Voc of HIT cell. In addition, it can improve the conductivity of TCO layer, and reduce Ag/TCO contact resistance, thus improving the FF of HJT cell.
