Direct nm-scale spatial mapping of traps in CIGS

Using newly developed nanometer-scale deep level transient (nano-DLTS) spectroscopy, the spatial distribution of the Ev+0.47 eV trap in p-type Cu(In,Ga)Se-2 (CIGS) is mapped simultaneously with topography to correlate the electrical traps with physical structure. It is demonstrated that the Ev+0.47 eV trap properties using nano-DLTS match the observed macroscopic properties. Additionally, the Ev+0.47 eV map reveals that this trap is not uniformly distributed, is likely correlated with specific grain boundaries, and not related to all grain boundaries. The combined multi-scale approach reveals overall trap impact as well as correlation with physical structures on the nm-scale that can be broadly applied to any semiconductor material.