TY - JOUR AB - A robust, reproducible method for the extraction of relative bandgap trends from scanning transmission electron microscopy (STEM) based electron energy-loss spectroscopy (EELS) is described. The effectiveness of the approach is demonstrated by profiling the bandgap through a CuIn1-xGaxSe2 solar cell that possesses intentional Ga/(In + Ga) composition variation. The EELS-determined bandgap profile is compared to the nominal profile calculated from compositional data collected via STEM-based energy dispersive X-ray spectroscopy. The EELS based profile is found to closely track the calculated bandgap trends, with only a small, fixed offset difference. This method, which is particularly advantageous for relatively narrow bandgap materials and/or STEM systems with modest resolution capabilities (i.e., >100 meV), compromises absolute accuracy to provide a straightforward route for the correlation of local electronic structure trends with nanoscale chemical and physical structure/microstructure within semiconductor materials and devices. AU - Deitz,JI AU - Karki,S AU - Marsillac,SX AU - Grassman,TJ AU - McComb,DW DO - 10.1063/1.5011658 PY - 2018/// SN - 0021-8979 TI - Bandgap profiling in CIGS solar cells via valence electron energy-loss spectroscopy T2 - Journal of Applied Physics UR - http://dx.doi.org/10.1063/1.5011658 VL - 123 ER -