Papers by Gernot Pomrenke
Symposium E on Rare Earth Doped Semiconductors at the 1993 MRS Spring Meeting was considered by m... more Symposium E on Rare Earth Doped Semiconductors at the 1993 MRS Spring Meeting was considered by many participants as extremely useful with respect to collating information in this field, highlighting new developments, bringing the international research efforts together, and making new contacts. Of course, the outstanding success of tile symposium was due in no small part to the efforts of the speakers and authors who presented their work and composed the papers for tile proceedings. A joint session on "Rare Earth Doped Silicon," held together with Symposium B, Silicon-Based Optoelectronic Materials, was beneficial to both symposia. highlighting especially erbium doped silicon for optoelectronic applications. The proceedings from this symposium represent one of the first attempts to compile selected research pertaining to rare earths incorporated into technologically important semiconductors. The properties of rare earth ions in solids have been studied in detail for decades. but until recently this work was restricted to dominantly ionic hosts such as fluorides and oxides, and to a lesser extent to more covalently bonded hosts, such as tetrahedral Il-VI semiconductors. The idea of rare earth elements incorporated into covalent semiconductors such as GaAs and Si may be traced to a short communication in 1963 by R.L. Bell IJ. Appl. Phys. 34. 1563 (1963)] proposing a dc-pumped rare earth laser. At about the same time. three unpublished technical reports appeared as a result of U.S. Department of Defense sponsored research in rare earth doped Si. GaAs. and InP to fabricate LE-)s. Attempts by Lasher et al.. Betz et al.. and Richman et alto identify sharp 4f specific emissions in these hosts essentially failed. Perhaps due to competing research efforts in glasses and Il-VI semiconductors, or to the recognition of the difficulty in appreciably doping the materials with rare earths, no substantial efforts (aside from Pyshkin. Soy. Phys. Sernicond. 8, 912 (1975)] were reported for rare earth doped semiconductors until 1979-1981, a period which witnessed increased activity in the Soviet Union (Kasatkin, Masterov. Zakharenkov. and collaborators). rhese investigations were quickly followed by various definitive investigations at the Fraunhofer IAP in(Germany by Ennen, Schneider, Kaufmann, Pomrenke. and collaborators. Closely related research by Klein. Furneaux, and Henry which impacted this area showed that host-impurity energy transfer could produce lasing from a closed shell impurity (Fe) in a semiconductor (InP) [Appl. Phys. Lett. 42, 6l38 (1983)]. Research over the last decade has taken a more international flavor, with the interest in large part driven by the possibility of producing efficient, room temperature, electrically excited intracenter emissions for optoelectronic applications. A particularly newsworthy article hinted at lasing in InGaAsP:Er [Appl. Phys. Lett. 49, 1686 (1986)]. More recently the research interest has focused around erbium doped silicon, due to its optoelectronic possibilities in a developed silicon electronic technology. Internationally. the research efforts have shifted primarily to Japan, U.S.A., France. Italy, the Netherlands. and Great Britain. The need for this symposium was dictated by the significant recent national and international activities in investigating rare earth doped semiconductors, and by the common themes in issues related to detects, doping, growth, theory. and optoelectronics. The groundwork for the symposium was laid in the fall of 1991, while unsuccessfully attempting to organize a NATO workshop in this area with H. Gislason and B. Wessels. The current forum through the MRS allowed for the cross fertilization among fields in the material sciences, solid state physics, laser physics, spectroscopy, chemistry, and device physics. The objective of the symposium was to bring together the community of investigators, addressing in depth the unique properties of rare earth doped Group Ill-V, Group IV, and Il-VI semiconductors, addressing current trends in research, and identifying the potential for current and future electronic and optoelectronic applications. The symposium aimed to address a broad range of topics front the very fundamental to the more applied. Emphasis was on the Ill-V and Group Xi IV material systems, although issues associated with the growth and doping of epitaxial Il-VI systems and particular insulators were also desired. Topics which were considered included defect theory, growth and implantation, microstructure, optical and electrical characterization, radiation damage, and specific device applications. These topics are reflected in the subject breakdown for the proceedings.
Rare earth doped semiconductors : symposium held April 13-15, 1993, San Francisco, California, U.S.A
Abstract : The properties of rare earth ions in solids have been studied in detail for decades, b... more Abstract : The properties of rare earth ions in solids have been studied in detail for decades, but until recently this work was restricted to dominantly ionic hosts such as fluorides and oxides, and to a lesser extent to more covalently bonded hosts, such as tetrahedral II-VI semiconductors. The idea of rare earth elements incorporated into covalent semiconductors such as GaAs and Si may be traced to a short communication in 1963 by R.L. Bell (J. Appl. Phys. 34, 1563 (1963)) proposing a dc-pumped rare earth laser. At about the same time, three unpublished technical reports appeared as a result of U.S. Department of Defense sponsored research in rare earth doped Si, GaAs, and InP to fabricate LEDs. Attempts by Lasher et al., Betz et al., and Richman et al. to identify sharp 4f specific emissions in these hosts essentially failed
We determined the molecular basis for the enhanced expression of the aac(3)-Xa gene encoding an a... more We determined the molecular basis for the enhanced expression of the aac(3)-Xa gene encoding an aminoglycoside 3-N-acetyltransferase in Streptomyces griseus. A C3T substitution was identified at the putative promoter of the mutant gene. RNA analyses demonstrated that the substitution caused a marked increase in the production of the gene-specific transcripts. Therefore, it seemed very likely that the aac(3)-Xa gene was activated by the substitution resulting in the emergence of a stronger promoter.
We determined the molecular basis for the enhanced expression of the aac(3)-Xa gene encoding an a... more We determined the molecular basis for the enhanced expression of the aac(3)-Xa gene encoding an aminoglycoside 3-N-acetyltransferase in Streptomyces griseus. A C3T substitution was identified at the putative promoter of the mutant gene. RNA analyses demonstrated that the substitution caused a marked increase in the production of the gene-specific transcripts. Therefore, it seemed very likely that the aac(3)-Xa gene was activated by the substitution resulting in the emergence of a stronger promoter.
: The Nanoscale Science, Engineering, and Technology Subcommittee of the National Science and Tec... more : The Nanoscale Science, Engineering, and Technology Subcommittee of the National Science and Technology Council's Committee on Technology, working through the National Nanotechnology Coordination Office, convened the Nanotechnology-Enabled Sensing Workshop to identify high-impact opportunities for the application of nanotechnology to sensing systems and to identify worthwhile research directions for nanotechnologies that are key to new sensing applications. The workshop was held May 5-7, 2009, at the Sheraton National Hotel in Arlington, Virginia. The agenda (see Appendix A) encompassed a mixture of talks, breakout sessions, and writing group meetings. The two days of the public workshop (May 5-6) began with plenary presentations on sensors and areas where nanotechnology can impact sensing systems. These broad overviews were followed by short, focused presentations on specific types of nanotechnology-enabled transducers and the challenges associated with fabricating, integratin...
: The Nanoscale Science, Engineering, and Technology Subcommittee of the National Science and Tec... more : The Nanoscale Science, Engineering, and Technology Subcommittee of the National Science and Technology Council's Committee on Technology, working through the National Nanotechnology Coordination Office, convened the Nanotechnology-Enabled Sensing Workshop to identify high-impact opportunities for the application of nanotechnology to sensing systems and to identify worthwhile research directions for nanotechnologies that are key to new sensing applications. The workshop was held May 5-7, 2009, at the Sheraton National Hotel in Arlington, Virginia. The agenda (see Appendix A) encompassed a mixture of talks, breakout sessions, and writing group meetings. The two days of the public workshop (May 5-6) began with plenary presentations on sensors and areas where nanotechnology can impact sensing systems. These broad overviews were followed by short, focused presentations on specific types of nanotechnology-enabled transducers and the challenges associated with fabricating, integratin...
Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1992
Sharp, well-resolved near band-edge photoluminescence (PL) has been observed from longperiod Si1_... more Sharp, well-resolved near band-edge photoluminescence (PL) has been observed from longperiod Si1_xGexlSi superlattices grown by molecular-beam epitaxy, including PL from a 120 A Sil40 A Sil _xGe x sample. The sharp PL is due to shallow bound excitons (BE), and consists of a no-phonon (NP) line as well as phonon-assisted lines. The exciton binding energies obtained from the temperature dependence of the BE(NP) lines are in the range of 4-6 meV.
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1992
Sharp, well-resolved near band-edge photoluminescence (PL) has been observed from longperiod Si1_... more Sharp, well-resolved near band-edge photoluminescence (PL) has been observed from longperiod Si1_xGexlSi superlattices grown by molecular-beam epitaxy, including PL from a 120 A Sil40 A Sil _xGe x sample. The sharp PL is due to shallow bound excitons (BE), and consists of a no-phonon (NP) line as well as phonon-assisted lines. The exciton binding energies obtained from the temperature dependence of the BE(NP) lines are in the range of 4-6 meV.
Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
1997 Advanced Workshop on Frontiers in Electronics, WOFE '97 Proceedings
1997 Advanced Workshop on Frontiers in Electronics WOFE 97 Proceedings WOFE-97, 1997
Abstract: The goal of this Workshop was to bring together leading scientists and engineers who ar... more Abstract: The goal of this Workshop was to bring together leading scientists and engineers who are at the frontiers of electronic device and circuit research and development but who approach this technology for entirely different directions. The Workshop sessions included a Digital, ...
1997 Advanced Workshop on Frontiers in Electronics, WOFE '97 Proceedings
1997 Advanced Workshop on Frontiers in Electronics WOFE 97 Proceedings WOFE-97, 1997
Abstract: The goal of this Workshop was to bring together leading scientists and engineers who ar... more Abstract: The goal of this Workshop was to bring together leading scientists and engineers who are at the frontiers of electronic device and circuit research and development but who approach this technology for entirely different directions. The Workshop sessions included a Digital, ...
Annealing Studies of Er-Implanted GaAs and the Excitation Mechanism of Er in GaAs
MRS Proceedings, 1993
ABSTRACTElectrical and optical measurements were performed on p-type GaAs implanted with 1013 Er ... more ABSTRACTElectrical and optical measurements were performed on p-type GaAs implanted with 1013 Er ions/cm2 at an energy of 1 MeV. The samples were annealed at 650, 750, 850, or 900 °C for 15 seconds using the rapid thermal annealing technique. Although annealing at 650 °C was insufficient to recover measureable electrical conductivity in the implanted region, Er3+ 4f-4f emissions were still observed. Annealing at 750 TC produced a large concentration of hole traps at EV + 360 meV, and the most intense Er-related emissions at 1.54 μm. The two higher annealing temperatures returned the implanted region to the conductivity of the substrate but resulted in weak Er-related emissions. Two distinct Er-related centers were found, and they are believed to be the cause of the intense and weak emissions, an Er-interstitial and Er substituting for Ga, respectively.
Annealing Studies of Er-Implanted GaAs and the Excitation Mechanism of Er in GaAs
MRS Proceedings, 1993
ABSTRACTElectrical and optical measurements were performed on p-type GaAs implanted with 1013 Er ... more ABSTRACTElectrical and optical measurements were performed on p-type GaAs implanted with 1013 Er ions/cm2 at an energy of 1 MeV. The samples were annealed at 650, 750, 850, or 900 °C for 15 seconds using the rapid thermal annealing technique. Although annealing at 650 °C was insufficient to recover measureable electrical conductivity in the implanted region, Er3+ 4f-4f emissions were still observed. Annealing at 750 TC produced a large concentration of hole traps at EV + 360 meV, and the most intense Er-related emissions at 1.54 μm. The two higher annealing temperatures returned the implanted region to the conductivity of the substrate but resulted in weak Er-related emissions. Two distinct Er-related centers were found, and they are believed to be the cause of the intense and weak emissions, an Er-interstitial and Er substituting for Ga, respectively.
Excitation Mechanism of the Erbium 4F Emissions in GaAs
Materials Science Forum, 1992
Excitation Mechanism of the Erbium 4F Emissions in GaAs
Materials Science Forum, 1992
Air Force Efforts in Nanoscience and Nanotechnology - Investment and Leverage
Infotech@Aerospace, 2005
*** The Air Force Research Laboratory has a program in nanoscience that is broadly based in the L... more *** The Air Force Research Laboratory has a program in nanoscience that is broadly based in the Laboratory, with participation from all parts of AFRL. Following an extensive program development and planning activity, the program has selected areas for concentration to make the best use of limited funding. It has also had success in leveraging the program with well funded programs in the Pacific Rim countries, Taiwan and Korea. The resulting program is well positioned to produce quality research leading to future generations of aerospace products. The program is also assisted through important linkages with university research in the US, including a partnership with seven Texas Universities in the SPRING program.
Air Force Efforts in Nanoscience and Nanotechnology - Investment and Leverage
Infotech@Aerospace, 2005
*** The Air Force Research Laboratory has a program in nanoscience that is broadly based in the L... more *** The Air Force Research Laboratory has a program in nanoscience that is broadly based in the Laboratory, with participation from all parts of AFRL. Following an extensive program development and planning activity, the program has selected areas for concentration to make the best use of limited funding. It has also had success in leveraging the program with well funded programs in the Pacific Rim countries, Taiwan and Korea. The resulting program is well positioned to produce quality research leading to future generations of aerospace products. The program is also assisted through important linkages with university research in the US, including a partnership with seven Texas Universities in the SPRING program.
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Papers by Gernot Pomrenke