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Title: Band gap tuning of InAs/InP quantum sticks using low-energy ion-implantation-induced intermixing

Abstract

Low-energy (18 keV) phosphorus ion implantation and rapid thermal annealing at 650 deg. C for 120 s were used to create point defects and promote intermixing in InAs/InP quantum stick structures grown by molecular beam epitaxy. With these soft conditions for ion-implantation-induced intermixing, photoluminescence measurements at low temperature show a very large blueshift up to 350 nm and a narrow emission linewidth (down to 30 nm for ion dose equal to 5x10{sup 13} cm{sup -2}). The band gap tuning limit in this system was evaluated using implantation of phosphorus ions at various doses (1x10{sup 11}-5x10{sup 14} cm{sup -2}), at a temperature of 200 deg. C followed by rapid thermal annealing.

Authors:
; ; ; ; ;  [1];  [2]
  1. Centre de Recherche en Nanofabrication et Nanocaracterisation (CRN2), Universite de Sherbrooke (Quebec) J1K 2R1 (Canada)
  2. (France)
Publication Date:
OSTI Identifier:
20706476
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 87; Journal Issue: 24; Other Information: DOI: 10.1063/1.2142330; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANNEALING; CRYSTAL GROWTH; ENERGY GAP; INDIUM ARSENIDES; INDIUM PHOSPHIDES; ION IMPLANTATION; KEV RANGE 10-100; MOLECULAR BEAM EPITAXY; MOLECULAR STRUCTURE; NANOSTRUCTURES; PHOSPHORUS IONS; PHOTOLUMINESCENCE; POINT DEFECTS; SEMICONDUCTOR MATERIALS; SPECTRAL SHIFT; TEMPERATURE RANGE 0400-1000 K

Citation Formats

Salem, B., Aimez, V., Morris, D., Turala, A., Regreny, P., Gendry, M., and Laboratoire d'Electronique, Optoelectronique et Microsystemes - LEOM, UMR CNRS 5512, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, 69134 Ecully Cedex. Band gap tuning of InAs/InP quantum sticks using low-energy ion-implantation-induced intermixing. United States: N. p., 2005. Web. doi:10.1063/1.2142330.
Salem, B., Aimez, V., Morris, D., Turala, A., Regreny, P., Gendry, M., & Laboratoire d'Electronique, Optoelectronique et Microsystemes - LEOM, UMR CNRS 5512, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, 69134 Ecully Cedex. Band gap tuning of InAs/InP quantum sticks using low-energy ion-implantation-induced intermixing. United States. doi:10.1063/1.2142330.
Salem, B., Aimez, V., Morris, D., Turala, A., Regreny, P., Gendry, M., and Laboratoire d'Electronique, Optoelectronique et Microsystemes - LEOM, UMR CNRS 5512, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, 69134 Ecully Cedex. Mon . "Band gap tuning of InAs/InP quantum sticks using low-energy ion-implantation-induced intermixing". United States. doi:10.1063/1.2142330.
@article{osti_20706476,
title = {Band gap tuning of InAs/InP quantum sticks using low-energy ion-implantation-induced intermixing},
author = {Salem, B. and Aimez, V. and Morris, D. and Turala, A. and Regreny, P. and Gendry, M. and Laboratoire d'Electronique, Optoelectronique et Microsystemes - LEOM, UMR CNRS 5512, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, 69134 Ecully Cedex},
abstractNote = {Low-energy (18 keV) phosphorus ion implantation and rapid thermal annealing at 650 deg. C for 120 s were used to create point defects and promote intermixing in InAs/InP quantum stick structures grown by molecular beam epitaxy. With these soft conditions for ion-implantation-induced intermixing, photoluminescence measurements at low temperature show a very large blueshift up to 350 nm and a narrow emission linewidth (down to 30 nm for ion dose equal to 5x10{sup 13} cm{sup -2}). The band gap tuning limit in this system was evaluated using implantation of phosphorus ions at various doses (1x10{sup 11}-5x10{sup 14} cm{sup -2}), at a temperature of 200 deg. C followed by rapid thermal annealing.},
doi = {10.1063/1.2142330},
journal = {Applied Physics Letters},
number = 24,
volume = 87,
place = {United States},
year = {Mon Dec 12 00:00:00 EST 2005},
month = {Mon Dec 12 00:00:00 EST 2005}
}
  • We report on the effects of the As/P intermixing induced by phosphorus ion implantation in InAs/InP quantum dashes (QDas) on their photoluminescence (PL) properties. For nonintermixed QDas, usual temperature-dependent PL properties characterized by a monotonic redshift in the emission band and a continual broadening of the PL linewidth as the temperature increases, are observed. For intermediate ion implantation doses, the inhomogeneous intermixing enhances the QDas size dispersion and the enlarged distribution of carrier confining potential depths strongly affects the temperature-dependent PL properties below 180 K. An important redshift in the PL emission band occurs between 10 and 180 K whichmore » is explained by a redistribution of carriers among the different intermixed QDas of the ensemble. For higher implantation doses, the homogeneous intermixing reduces the broadening of the localized QDas state distribution and the measured linewidth temperature behavior matches that of the nonintermixed QDas. An anomalous temperature-dependent emission energy behavior has been observed for extremely high implantation doses, which is interpreted by a possible QDas dissolution.« less
  • Inductively coupled argon plasma-enhanced intermixing of InAs/InP quantum dots grown on InP substrate is investigated. Intermixing is promoted by the near-surface defects generated by plasma exposure in annealing at a temperature of 600 deg. C for 30 s. The annealing results in a maximum differential band-gap blueshift of 106 nm but a thermal shift of only 10 nm. Band-gap halftones are obtained by controlling the amount of near-surface defects via wet chemical etching on the plasma-exposed InP cap layer. No degradation of quantum-dot crystal quality due to the process has been observed as evidenced by photoluminescence intensity.
  • We have investigated the influence of defects emanating from phosphorus implantation damage in the InP capping layer on postgrowth thermally induced intermixing in self-assembled InAs/InP(001) quantum dots (QDs). Photoluminescence (PL) spectra from as-grown samples could be described as the superposition of separate PL peaks where each peak corresponded to emission from an ensemble of QDs with a particular height ranging from 4 to 13 ML. Blueshift of up to 270 meV and significant bandwidth broadening were observed in the PL spectra after ion implantation with a fluence of 5x10{sup 11}-10{sup 14} cm{sup -2} and subsequent annealing at temperatures ranging frommore » 450 to 600 deg. C. From the analysis of the evolution of the QD peaks upon intermixing, which revealed the coexistence of intact QD PL and a broad PL feature related to heavily intermixed QDs, it was suggested that the bandwidth broadening resulted from spatial inhomogeneity in the compositional intermixing. In order to better understand the mechanism responsible for the ion-implantation-induced intermixing, samples capped with a stack of compressively strained In{sub 0.75}Ga{sub 0.25}As/InP quantum wells (QWs) were prepared to trap vacancies released by the implantation damage while not inhibiting the effect of the interstitials. Both blueshift and bandwidth broadening were suppressed in samples containing the strained InGaAs QWs, whereas the evolution of the PL spectra from the QDs behaves as expected for interstitial-mediated intermixing. The vacancies were thus believed to be trapped in the QWs and indicated that intermixing in ion-implanted InP capped samples is mediated by vacancies. The shape of the QDs changed from a truncated pyramid in the as-grown state to a double convex lens structure after intermixing as confirmed by cross-sectional scanning transmission electron microscopy imaging. Furthermore, the change in shape and compositional intermixing of the QDs were attributed to vacancy trapping in the vicinity of the QDs as based on atomistic strain calculations.« less
  • We have applied ion channeling techniques to investigate effects of proton irradiation combined with thermal annealing on In-Ga atomic intermixing in a self-assembled InAs/GaAs quantum dot (QD) system. A molecular-beam-epitaxy grown InAs/GaAs QD sample was first irradiated with 1.0 MeV protons to a dose of 10{sup 14} cm{sup -2} and subsequently annealed at temperatures between 300-700 deg. C. Ion channeling measurements indicate that such postgrowth processing leads to an enhanced amount of In atoms registering along the <100> growth direction. This observation yields direct evidence for the occurrence of In-Ga atomic intermixing in the QD structure during postirradiation annealing. Themore » effective activation energy for such intermixing process is determined to be {approx}0.2 eV. Furthermore, ion channeling data suggest three distinct stages for In-Ga atomic intermixing processes in the QD system, with In-Ga interdiffusion proceeding vertically along the growth direction or laterally in the QD layer, depending on postirradiation annealing temperatures.« less
  • Graphical abstract: - Abstract: Here we propose a carrier transport mechanism for low energy H{sup −} ions implanted InAs/GaAs quantum dot infrared photodetectors supportive of the experimental results obtained. Dark current density suppression of up to four orders was observed in the implanted quantum dot infrared photodetectors, which further demonstrates that they are effectively operational. We concentrated on determining how defect-related material and structural changes attributed to implantation helped in dark current density reduction for InAs/GaAs quantum dot infrared photodetectors. This is the first study to report the electrical carrier transport mechanism of H{sup −} ion-implanted InAs/GaAs quantum dot infraredmore » photodetectors.« less