Study of the previous light-soaking effect on annealed hydrogenated polymorphous silicon solar cells structures

This work describes a study performed on pm-Si:H PIN and NIP structures, deposited by PECVD. We show the effect of light-soaking (AM1.5) on pm-Si:H thin films structures optical properties. We propose a model for long range diffusion of hydrogen through the whole device. From the evolution of Raman spectra after annealing, we show that this long range motion of hydrogen causes a hydrogen rearrangement on the film along with a shift on the exodiffusion peaks explaining the degradation process in this type of devices. As a result we determined that for the PIN structure a hydrogen diffusion barrier is generated by defects, which causes a less degradation of its optoelectronic properties under illumination, and a more stable device during operation is expected.