Residual stress analysis of thin film photovoltaic cells subjected to massive micro-particle impact

Residual stresses play a crucial role in both light-electricity conversion performances and the lifespan of photovoltaic (PV) cells. In this paper, the residual stress of triple junction cells (i.e. GaInP/GaInAs/Ge) induced by laser-driven massive micro-particle impact is analyzed with a novel method based on backscattering Raman spectroscopy. The impact process, which induces damage to the PV cells and brings the residual stress, is also investigated by optical microscopy (OM) and Scanning Electron Microscopy (SEM). The results show that the PV cells would exhibit various damage patterns. At the same time, strong residual stresses up to hundreds of MPa introduced in the damaged PV cells after impact have been analysis, providing an effective perspective to better understand the damage behavior and residual stress features of PV cells during their service life.