Energy-band alignment of II-VI/Zn3P2 heterojunctions from x-ray photoemission spectroscopy
Citation:
Bosco, J.P., Scanlon, D.O., Watson, G.W., Lewis, N.S., Atwater, H.A., Energy-band alignment of II-VI/Zn3P2 heterojunctions from x-ray photoemission spectroscopy, Journal of Applied Physics, 113, 20, 2013, art. no. 203705Download Item:
Abstract:
The energy-band alignments for zb-ZnSe(001)/
a
-Zn
3
P
2
(001), w-CdS(0001)/
a
-Zn
3
P
2
(001), and
w-ZnO(0001)/
a
-Zn
3
P
2
(001) heterojunctions have been determined using high-resolution x-ray
photoelectron spectroscopy via the Kraut method.
Ab initio
hybrid density functional theory
calculations of the valence-band density of states were used to determine the energy differences
between the core level and valence-band maximum for each of the bulk materials. The ZnSe/Zn
3
P
2
heterojunction had a small conduction-band offset,
D
E
C
,of
0.03
6
0.11eV, demonstrating a
nearly ideal energy-band alignment for use in thin-film photovoltaic devices. The CdS/Zn
3
P
2
heterojunction was also type-II but had a larger conduction-band offset of
D
E
C
?
0.76
6
0.10eV.
A type-III alignment was observed for the ZnO/Zn
3
P
2
heterojunction, with
D
E
C
?
1.61
6
0.16eV
indicating the formation of a tunnel junction at the oxide?phosphide interface. The data also provide
insight into the role of the II-VI/Zn
3
P
2
band alignment in the reported performance of Zn
3
P
2
heterojunction solar cells
Sponsor
Grant Number
Engineering and Physical Sciences Research Council (EPSRC)
EP/F067496
Author's Homepage:
http://people.tcd.ie/watsongDescription:
PUBLISHED
Author: WATSON, GRAEME
Sponsor:
Engineering and Physical Sciences Research Council (EPSRC)Type of material:
Journal ArticleCollections
Series/Report no:
Journal of Applied Physics113
20
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Full text availableKeywords:
PhysicsDOI:
http://dx.doi.org/10.1063/1.4807646Metadata
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