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Franz-Keldysh effect in GaN nanowires

Abstract

In recent years III-nitride based nanowires have attracted a lot of interest because of their potential applications for nanoelectronic devices. Due to the large surface-to-volume ratio of the wires, the optoelectronic properties as well as growth processes are essentially dependent on the wire diameter. We have studied GaN NWs obtained by catalyst-free radio frequency PAMBE on Si(111) in N-rich conditions. Surface Photovoltage Spectroscopy and Spectral Photoconductivity (SPC) measurements have been carried out to analyze the near band-edge absorption in GaN nanowires. A strong diameter dependence of the band absorption tail was found by SPC measurements. The band-edge tailoring and its wire-diameter dependence can be explained by the Franz-Keldysh effect induced by the electric field at the wire surface. The experimental values of the absorption tail are well in agreement with the results obtained by simulating the electric field in a cylindrical model.
Authors:
Calarco, Raffaella; Stoica, Toma; Meijers, Ralph; Richter, Thomas; Lueth, Hans; [1]  Research Center Juelich (Germany). cni - Center of Nanoelectronic Systems for Information Technology]; Cavallini, Anna; Polenta, Laura; Rossi, Marco; [2]  CNISM, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy)]
  1. Institute of Bio- and Nanosystems (IBN1), Research Centre Juelich, 52425 Juelich (Germany)
  2. Phys. Department, CNISM, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy)
Publication Date:
Jul 01, 2008
Product Type:
Journal Article
Resource Relation:
Journal Name: Verhandlungen der Deutschen Physikalischen Gesellschaft; Journal Volume: 43; Journal Issue: 1; Conference: 72. annual meeting and DPG (Deutsche Physikalische Gesellschaft e.V.) Spring meeting of the Condensed Matter Section and the Divisions: Physics Education, History of Physics, Radiation and Medical Physics as well as the Working Groups Equal Opportunities, Industry and Business, Information, Physics and Disarmament, Physics of Socio-economic Systems, Young DPG, 72. Jahrestagung und DPG (Deutsche Physikalische Gesellschaft e.V.) Fruehjahrstagung der Sektion Kondensierte Materie und den Fachverbaenden: Didaktik der Physik, Geschichte der Physik, Strahlen- und Medizinphysik und den Arbeitskreisen Chancengleichheit, Industrie und Wirtschaft, Information, Physik und Abruestung, Physik Sozio-oekonomischer Systeme, Junge DPG, Berlin (Germany), 25-29 Feb 2008; Other Information: Session: HL 23.7 Di 12:30; No further information available
Subject:
36 MATERIALS SCIENCE; GALLIUM NITRIDES; QUANTUM WIRES; PLASMA; MOLECULAR BEAM EPITAXY; SILICON; SURFACES; SUBSTRATES; WIDTH; BAND THEORY; ELECTRONIC STRUCTURE; ELECTRIC FIELDS; ABSORPTION SPECTRA
OSTI ID:
21169081
Country of Origin:
Germany
Language:
English
Other Identifying Numbers:
Journal ID: ISSN 0420-0195; VDPEAZ; TRN: DE09G5949
Availability:
Also available online: http://www.dpg-tagungen.de/index_en.html
Submitting Site:
DE
Size:
1 pages
Announcement Date:
May 28, 2009

Citation Formats

Calarco, Raffaella, Stoica, Toma, Meijers, Ralph, Richter, Thomas, Lueth, Hans, Research Center Juelich (Germany). cni - Center of Nanoelectronic Systems for Information Technology], Cavallini, Anna, Polenta, Laura, Rossi, Marco, and CNISM, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy)]. Franz-Keldysh effect in GaN nanowires. Germany: N. p., 2008. Web.
Calarco, Raffaella, Stoica, Toma, Meijers, Ralph, Richter, Thomas, Lueth, Hans, Research Center Juelich (Germany). cni - Center of Nanoelectronic Systems for Information Technology], Cavallini, Anna, Polenta, Laura, Rossi, Marco, & CNISM, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy)]. Franz-Keldysh effect in GaN nanowires. Germany.
Calarco, Raffaella, Stoica, Toma, Meijers, Ralph, Richter, Thomas, Lueth, Hans, Research Center Juelich (Germany). cni - Center of Nanoelectronic Systems for Information Technology], Cavallini, Anna, Polenta, Laura, Rossi, Marco, and CNISM, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy)]. 2008. "Franz-Keldysh effect in GaN nanowires." Germany.
@misc{etde_21169081,
title = {Franz-Keldysh effect in GaN nanowires}
author = {Calarco, Raffaella, Stoica, Toma, Meijers, Ralph, Richter, Thomas, Lueth, Hans, Research Center Juelich (Germany). cni - Center of Nanoelectronic Systems for Information Technology], Cavallini, Anna, Polenta, Laura, Rossi, Marco, and CNISM, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy)]}
abstractNote = {In recent years III-nitride based nanowires have attracted a lot of interest because of their potential applications for nanoelectronic devices. Due to the large surface-to-volume ratio of the wires, the optoelectronic properties as well as growth processes are essentially dependent on the wire diameter. We have studied GaN NWs obtained by catalyst-free radio frequency PAMBE on Si(111) in N-rich conditions. Surface Photovoltage Spectroscopy and Spectral Photoconductivity (SPC) measurements have been carried out to analyze the near band-edge absorption in GaN nanowires. A strong diameter dependence of the band absorption tail was found by SPC measurements. The band-edge tailoring and its wire-diameter dependence can be explained by the Franz-Keldysh effect induced by the electric field at the wire surface. The experimental values of the absorption tail are well in agreement with the results obtained by simulating the electric field in a cylindrical model.}
journal = {Verhandlungen der Deutschen Physikalischen Gesellschaft}
issue = {1}
volume = {43}
place = {Germany}
year = {2008}
month = {Jul}
}