The University of Southampton
University of Southampton Institutional Repository

Non-equilibrium doping of amorphous chalcogenides

Non-equilibrium doping of amorphous chalcogenides
Non-equilibrium doping of amorphous chalcogenides
The doping of amorphous chalcogenides to control their electronic properties, and specifically change the dominant charge carrier type from holes to electrons, has been a major research challenge for many years. Generally attempts to achieve this through doping during the glass forming phase have been frustrated by autocompensation effects mediated via charged defects resulting in Fermi level pinning. To date progress in this area has remained limited to Bi and Pb-doped GeX (X = S, Se, Te) systems where high doping levels (6-11%) have shown carrier type reversal (CTR) from p-type to n-type.
We have readdressed the issue of CTR in amorphous chalcogenides by exploring the concept of non-equilibrium doping, corresponding to the introduction of dopants into the glass matrix following the formation of the network. To achieve this we utilize ion-implantation thereby enabling doping with a wide choice of ion species into any solid chalcogenide system. A number of amorphous chalcogenides systems have been studied including GeX, Ge2Sb2Te5 and GaLaS-based glasses deposited onto substrates via sputtering to form thin films. The structural, electrical and optical properties of the doped systems have been studied in detail revealing their significant modification and aiding understanding of the effect of non-equilibrium doping on these various systems. In particular a series of fabricated chalcogenide/n(p)-type Si devices enable detailed examination of the role of trap states in determining the electrical properties.
We demonstrate the success of our non-equilibrium doping approach through achieving CTR in the GeX systems as lower doping concentrations than previously shown possible using conventional approaches. Furthermore, we demonstrate CTR for the first time in a non-GeX system, demonstrating the fabrication of pn-junction devices which are characterized for their electronic and optical behavior.
Curry, R.J.
1ae2a4da-7efe-4333-a34e-0ec20ae95154
Federenko, Y.
e585ae8a-225a-4866-9ea1-a2c5d08330d5
Hughes, M.A.
15c829d1-0f1b-454b-aa39-6bb53556914a
Gwilliam, R.M.
e856c9bd-c0f3-4ac4-adbe-4835e9c9923e
Homewood, K.P.
b7fcd4f3-6d6c-4610-be18-05dc7d090b80
Gholipour, B.
c17bd62d-9df6-40e6-bc42-65272d97e559
Yao, J.
83dff1cd-6f7c-4b47-968e-18c64ffcb24b
Hewak, D.W.
87c80070-c101-4f7a-914f-4cc3131e3db0
Lee, T.H.
a75905d5-edbf-4d6a-bde5-fea7fff21bad
Elliott, S.R.
14e14577-ad98-4ffb-8d0a-503c1022d5ff
Curry, R.J.
1ae2a4da-7efe-4333-a34e-0ec20ae95154
Federenko, Y.
e585ae8a-225a-4866-9ea1-a2c5d08330d5
Hughes, M.A.
15c829d1-0f1b-454b-aa39-6bb53556914a
Gwilliam, R.M.
e856c9bd-c0f3-4ac4-adbe-4835e9c9923e
Homewood, K.P.
b7fcd4f3-6d6c-4610-be18-05dc7d090b80
Gholipour, B.
c17bd62d-9df6-40e6-bc42-65272d97e559
Yao, J.
83dff1cd-6f7c-4b47-968e-18c64ffcb24b
Hewak, D.W.
87c80070-c101-4f7a-914f-4cc3131e3db0
Lee, T.H.
a75905d5-edbf-4d6a-bde5-fea7fff21bad
Elliott, S.R.
14e14577-ad98-4ffb-8d0a-503c1022d5ff

Curry, R.J., Federenko, Y., Hughes, M.A., Gwilliam, R.M., Homewood, K.P., Gholipour, B., Yao, J., Hewak, D.W., Lee, T.H. and Elliott, S.R. (2014) Non-equilibrium doping of amorphous chalcogenides. ICOOPMA '14: Sixth International Conference on Optical, Optoelectronic and Photonic Materials and Applications, Leeds, United Kingdom. 27 Jul - 31 Aug 2014.

Record type: Conference or Workshop Item (Paper)

Abstract

The doping of amorphous chalcogenides to control their electronic properties, and specifically change the dominant charge carrier type from holes to electrons, has been a major research challenge for many years. Generally attempts to achieve this through doping during the glass forming phase have been frustrated by autocompensation effects mediated via charged defects resulting in Fermi level pinning. To date progress in this area has remained limited to Bi and Pb-doped GeX (X = S, Se, Te) systems where high doping levels (6-11%) have shown carrier type reversal (CTR) from p-type to n-type.
We have readdressed the issue of CTR in amorphous chalcogenides by exploring the concept of non-equilibrium doping, corresponding to the introduction of dopants into the glass matrix following the formation of the network. To achieve this we utilize ion-implantation thereby enabling doping with a wide choice of ion species into any solid chalcogenide system. A number of amorphous chalcogenides systems have been studied including GeX, Ge2Sb2Te5 and GaLaS-based glasses deposited onto substrates via sputtering to form thin films. The structural, electrical and optical properties of the doped systems have been studied in detail revealing their significant modification and aiding understanding of the effect of non-equilibrium doping on these various systems. In particular a series of fabricated chalcogenide/n(p)-type Si devices enable detailed examination of the role of trap states in determining the electrical properties.
We demonstrate the success of our non-equilibrium doping approach through achieving CTR in the GeX systems as lower doping concentrations than previously shown possible using conventional approaches. Furthermore, we demonstrate CTR for the first time in a non-GeX system, demonstrating the fabrication of pn-junction devices which are characterized for their electronic and optical behavior.

Full text not available from this repository.

More information

e-pub ahead of print date: 2014
Venue - Dates: ICOOPMA '14: Sixth International Conference on Optical, Optoelectronic and Photonic Materials and Applications, Leeds, United Kingdom, 2014-07-27 - 2014-08-31
Organisations: Optoelectronics Research Centre, Electrochemistry

Identifiers

Local EPrints ID: 375954
URI: http://eprints.soton.ac.uk/id/eprint/375954
PURE UUID: b69cb204-2b3b-45a8-9fd0-10248d9e4aed
ORCID for D.W. Hewak: ORCID iD orcid.org/0000-0002-2093-5773

Catalogue record

Date deposited: 21 Apr 2015 14:23
Last modified: 21 Mar 2019 01:36

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×