Imperial College London

Professor David W. McComb

Faculty of EngineeringDepartment of Materials

Adjunct Professor



+44 (0)20 7594 6750d.mccomb Website




Royal School of MinesSouth Kensington Campus






BibTex format

author = {Deitz, JI and Karki, S and Marsillac, SX and Grassman, TJ and McComb, DW},
doi = {10.1063/1.5011658},
journal = {Journal of Applied Physics},
title = {Bandgap profiling in CIGS solar cells via valence electron energy-loss spectroscopy},
url = {},
volume = {123},
year = {2018}

RIS format (EndNote, RefMan)

AB - © 2018 Author(s). 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 -
VL - 123
ER -