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 Paul, PK and Karki, S and Marsillac, SX and Arehart, AR and Grassman, TJ and McComb, DW},
doi = {10.1109/PVSC.2018.8547398},
pages = {3914--3917},
title = {Nanoscale Electronic Structure Characterization in CIGS with Electron Energy-Loss Spectroscopy},
url = {},
year = {2018}

RIS format (EndNote, RefMan)

AB - © 2018 IEEE. Electron energy-loss spectroscopy (EELS) within a monochromated scanning transmission electron microscope (STEM) was used to provide electronic structure characterization of CuIn 1-x Ga x Se 2 (CIGS) solar cells. Two applications within this context were explored: Spatially-resolved bandgap profiling using a newly-developed and simplified analysis approach, and detection of sub-gap defect states with high energy and spatial resolution. The simplified STEM-EELS bandgap profiling method was found to closely track nominal bandgap trends calculated from compositional data, with only a small, fixed offset (0.35 eV). Sub-gap energy levels in two different CIGS samples were identified at EV + 0.43 eV and EV + 0.56 eV, 0.56 eV, exactly consistent (i.e.< 0.01 eV discrepancy) with trap states measured via conventional deep level transient spectroscopy (DLTS) in both cases. Furthermore, direct correlation between STEM-EELS and scanning DLTS (S-DLTS) measurements made at the same sample site providing strong confirmation that the energy levels detected via STEM-EELS are indeed the same trap levels detected via (S-)DLTS.
AU - Deitz,JI
AU - Paul,PK
AU - Karki,S
AU - Marsillac,SX
AU - Arehart,AR
AU - Grassman,TJ
AU - McComb,DW
DO - 10.1109/PVSC.2018.8547398
EP - 3917
PY - 2018///
SP - 3914
TI - Nanoscale Electronic Structure Characterization in CIGS with Electron Energy-Loss Spectroscopy
UR -
ER -