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Title: Isotopically engineered semiconductors: from the bulk tonanostructures

Abstract

Research performed with semiconductors with controlled isotopic composition is evolving from the measurement of fundamental properties in the bulk to those measured in superlattices and nanostructures. This is driven in part by interests associated with the fields of 'spintronics' and quantum computing. In this topical review, which is dedicated to Prof. Abstreiter, we introduce the subject by reviewing classic and recent measurements of phonon frequencies, thermal conductivity, bandgap renormalizations, and spin coherence lifetimes in isotopically controlled bulk group IV semiconductors. Next, we review phonon properties measured in isotope heterostructures, including pioneering work made possible by superlattices grown by the group of Prof. Abstreiter. We close the review with an outlook on the exciting future possibilities offered through isotope control in 1, 2, and 3 dimensions that will be possible due to advances in nanoscience.

Authors:
;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director. Office of Science. Basic EnergySciences
OSTI Identifier:
919505
Report Number(s):
LBNL-59997
Journal ID: ISSN 0031-8965; PSSABA; R&D Project: 513310; BnR: KC0201030; TRN: US200822%%375
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physica Status Solidi (a); Journal Volume: 203; Journal Issue: 14; Related Information: Journal Publication Date: 08/24/2006
Country of Publication:
United States
Language:
English
Subject:
36; DIMENSIONS; NANOSTRUCTURES; PHONONS; QUANTUM COMPUTERS; SPIN; SUPERLATTICES; THERMAL CONDUCTIVITY

Citation Formats

Ager III, Joel W., and Haller, Eugene E. Isotopically engineered semiconductors: from the bulk tonanostructures. United States: N. p., 2006. Web. doi:10.1002/pssa.200622390.
Ager III, Joel W., & Haller, Eugene E. Isotopically engineered semiconductors: from the bulk tonanostructures. United States. doi:10.1002/pssa.200622390.
Ager III, Joel W., and Haller, Eugene E. Fri . "Isotopically engineered semiconductors: from the bulk tonanostructures". United States. doi:10.1002/pssa.200622390.
@article{osti_919505,
title = {Isotopically engineered semiconductors: from the bulk tonanostructures},
author = {Ager III, Joel W. and Haller, Eugene E.},
abstractNote = {Research performed with semiconductors with controlled isotopic composition is evolving from the measurement of fundamental properties in the bulk to those measured in superlattices and nanostructures. This is driven in part by interests associated with the fields of 'spintronics' and quantum computing. In this topical review, which is dedicated to Prof. Abstreiter, we introduce the subject by reviewing classic and recent measurements of phonon frequencies, thermal conductivity, bandgap renormalizations, and spin coherence lifetimes in isotopically controlled bulk group IV semiconductors. Next, we review phonon properties measured in isotope heterostructures, including pioneering work made possible by superlattices grown by the group of Prof. Abstreiter. We close the review with an outlook on the exciting future possibilities offered through isotope control in 1, 2, and 3 dimensions that will be possible due to advances in nanoscience.},
doi = {10.1002/pssa.200622390},
journal = {Physica Status Solidi (a)},
number = 14,
volume = 203,
place = {United States},
year = {Fri Apr 07 00:00:00 EDT 2006},
month = {Fri Apr 07 00:00:00 EDT 2006}
}
  • The changes in phonon properties with isotopic composition also weakly affect the electronic band structures and the lattice constants. The latter isotope dependence is most relevant for future standards of length based on crystal lattice constants. Capture of thermal neutrons by isotope nuclei followed by nuclear decay produces new elements, resulting in a very large number of possibilities for isotope selective doping of semiconductors. This neutron transmutation of isotope nuclei, already used for homogeneous doping of floating zone Si with P, holds perhaps the biggest promises for isotopically controlled semiconductors and is discussed in some detail. Local vibrational modes ofmore » low-mass impurities are sensitive to the mass of the impurity as well as the masses of the host atoms neighboring the impurity. High-resolution infrared-absorption studies of O in Ge crystals of different isotopic composition demonstrate the extreme simplification in such spectra which is achieved by isotope control. Interdiffusion of GaAs and Ge isotope superlattices with 0.1--1 [mu]m thick layers have been studied with secondary-ion-mass spectroscopy. This kind of internal diffusion avoids the problems with surface effects and can produce accurate data without the need for radioactive tracers. The review closes with an outlook on the exciting future possibilities offered through isotope control of a wide range of semiconductor materials.« less
  • Neutral-impurity scattering of electrons and holes at low temperatures has been studied in isotopically engineered Ge single crystals. Use of the neutron transmutation doping technique provides the necessary dopant uniformity and low compensation. We find excellent agreement between the low-temperature experimental mobility and phase-shift calculations for the hydrogen atom scaled to the impurity atoms in semiconductors.
  • Incorporation of semiconductors into zeolites has been carried out to determine the effect of confinement on structure, dynamics and electrical properties. The semiconductors stabilized in the zeolite supercages, Se, RbSe and CsSe, are known to preserve their semiconducting behavior upon melting. Examination of the polycrystalline materials by TEM, Raman and anomalous X-ray diffraction show interesting behavior which is compared with that of the bulk materials of the guest species.