Understanding doping anomalies in degenerate p-type semiconductor LaCuOSe
Citation:
Scanlon,David O. D.O., Buckeridge,John J., Callow,C. Richard A. C.R.A., Watson,Graeme W. G.W., Understanding doping anomalies in degenerate p-type semiconductor LaCuOSe, Journal of Materials Chemistry C, 2, 17, 2014, 3429-3438Download Item:
c4tc00096j.pdf (PDF) 1.164Mb
Abstract:
The failure to develop a degenerate, wide band gap, p-type oxide material has been a stumbling block for
the optoelectronics industry for decades. Mg-doped LaCuOSe has recently emerged as a very promising
p-type anode layer for optoelectronic devices, displaying high conductivities and low hole injection
barriers. Despite these promising results, many questions regarding the defect chemistry of this system
remain unanswered, namely (i) why does this
degenerate
semiconductor not display a Moss
–
Burnstein
shift?, (ii) what is the origin of conductivity in doped and un-doped samples?, and (iii) why is Mg reported
to be the best dopant, despite the large cation size mismatch between Mg and La? In this article we use
screened hybrid density functional theory to study both intrinsic and extrinsic defects in LaCuOSe, and
identify for the
fi
rst time the source of charge carriers in this system. We successfully explain why
LaCuOSe does not exhibit a Moss
–
Burstein shift, and we identify the source of the subgap optical
absorption reported in experiments. Lastly we demonstrate that Mg doping
is not
the most e
ffi
cient
mechanism for p-type doping LaCuOSe, and propose an experimental reinvestigation of this system
Sponsor
Grant Number
Science Foundation Ireland (SFI)
6/IN.1/I92
Science Foundation Ireland (SFI)
06/IN.1/I92/EC07
Author's Homepage:
http://people.tcd.ie/watsongDescription:
PUBLISHED
Author: WATSON, GRAEME
Type of material:
Journal ArticleCollections:
Series/Report no:
Journal of Materials Chemistry C2
17
Availability:
Full text availableKeywords:
Mg dopingDOI:
http://dx.doi.org/10.1039/c4tc00096jISSN:
20507534Licences: