Imperial College London

Professor David W. McComb

Faculty of EngineeringDepartment of Materials

Adjunct Professor
 
 
 
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Contact

 

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

 
 
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Location

 

Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Deitz:2019:10.1002/aenm.201901612,
author = {Deitz, JI and Paul, PK and Farshchi, R and Poplavskyy, D and Bailey, J and Arehart, AR and McComb, DW and Grassman, TJ},
doi = {10.1002/aenm.201901612},
journal = {Advanced Energy Materials},
title = {Direct Nanoscale Characterization of Deep Levels in AgCuInGaSe<inf>2</inf> Using Electron Energy-Loss Spectroscopy in the Scanning Transmission Electron Microscope},
url = {http://dx.doi.org/10.1002/aenm.201901612},
volume = {9},
year = {2019}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim A new experimental framework for the characterization of defects in semiconductors is demonstrated. Through the direct, energy-resolved correlation of three analytical techniques spanning six orders of magnitude in spatial resolution, a critical mid-bandgap electronic trap level (EV + 0.56 eV) within Ag0.2Cu0.8In1−xGaxSe2 is traced to its nanoscale physical location and chemical source. This is achieved through a stepwise, site-specific correlated characterization workflow consisting of device-scale (≈1 mm2) deep level transient spectroscopy (DLTS) to survey the traps present, scanning probe–based DLTS (scanning-DLTS) for mesoscale-resolved (hundreds of nanometers) mapping of the target trap state's spatial distribution, and scanning transmission electron microscope based electron energy-loss spectroscopy (STEM-EELS) and X-ray energy-dispersive spectroscopy for nanoscale energy-, structure, and chemical-resolved investigation of the defect source. This first demonstration of the direct observation of sub-bandgap defect levels via STEM-EELS, combined with the DLTS methods, provides strong evidence that the long-suspected CuIn/Ga substitutional defects are indeed the most likely source of the EV + 0.56 eV trap state and serves as a key example of this approach for the fundamental identification of defects within semiconductors, in general.
AU - Deitz,JI
AU - Paul,PK
AU - Farshchi,R
AU - Poplavskyy,D
AU - Bailey,J
AU - Arehart,AR
AU - McComb,DW
AU - Grassman,TJ
DO - 10.1002/aenm.201901612
PY - 2019///
SN - 1614-6832
TI - Direct Nanoscale Characterization of Deep Levels in AgCuInGaSe<inf>2</inf> Using Electron Energy-Loss Spectroscopy in the Scanning Transmission Electron Microscope
T2 - Advanced Energy Materials
UR - http://dx.doi.org/10.1002/aenm.201901612
VL - 9
ER -