Solid-State Engineering

Externally Funded Research Projects

Electronic and Thermal Characterization of Solid Chalcogenides Using Molten Salts

Principal Investigator: C. R. Kannewurf

Sponsor: National Science Foundation (NSF), 12/95 – 11/99

A number of new compounds have been prepared of the type ALn3 Te8 (A = Cs or Rb, Ln = Ce;
A = K, Ln = Nd) which display an interesting defect square. For such materials, recent theory predicted a charge-density wave that leads to infinite zig-zag (Te2-2)n chains and Te2-3 anions.
The present work constitutes the first experimental confirmation of this prediction. The initial transport measurements on both single-crystal and pressed pellets samples indicate p-type conduction for narrow-gap semiconductors.

Electroactive Molecular & Polymeric Materials Thrust Group

Co-Principal Investigator: C. R. Kannewurf

Sponsor: NSF (Materials Research Center), 2/97 – 11/98

This is an ongoing investigation of polymer-based mixed conductors and nanocomposite materials such as the intercalation of polymers into semiconducting vanadium oxides. Attention is now also being given to possible organic device structures and conducting ceramics. Some of this work is a collaborative effort with other IRG groups of the Materials Research Center.

Electrical and Thermal Characterization for New Ternary Rare-Earth Based Materials for
High Performance Thermoelectrics

Principal Investigators: C. R. Kannewurf and M. G. Kanatzidis (Michigan State University)

Sponsor: Defense Advanced Research Projects Agency (DARPA) / Michigan State University,
1/98 – 12/01

The goal of this program is to discover new rare-earth and main-group-element materials having a high thermoelectric figure of merit. The focus is on: (a) narrow bandgap, heavy-element semiconductors; and (b) new ternary and quaternary compounds having itinerant electrons occupying a narrow distribution of energy near the Fermi level. These materials possess structural and electronic-band features that make them excellent candidates for use as thermoelectrics.

Transport Measurements for New Solid-State Ternary Bismuth Chalcogenides as
Thermoelectric Materials

Principal Investigator: C. R. Kannewurf

Sponsor: Office of Naval Research (ONR) / Michigan State University, 9/94 – 6/01

Electrical and thermal characterization studies are provided for the ternary chalcogenides.
Notable results have been obtained for R–Bi–Te (R = Cs, K) compositions. The current project determines doping levels to obtain the highest figure of merit for the most promising undoped samples, and extends the investigation to new bismuth chalcogenides.

MOCVD Research Project

Co-Principal Investigator: C. R. Kannewurf

Sponsor: NSF (Science and Technology Center for Superconductivity), 2/95 – 1/00

This program is now in its tenth year. A considerable effort has been spent on the determination of the key superconducting parameters for the thin-film project where the MOCVD preparation technique has been successfully employed for the major high-Tc systems. In collaboration with Argonne National Laboratory, recent work has involved the development of an ion-beam-assisted deposition system for preparing oxide buffer layers for the creation of coated conductors. The initial results for critical current density measurements are quite encouraging.

Improving the Quality of InGaAIN Thin-films Using a Fundamental Chemical Approach
Principal Investigator: N. Newman

Sponsor: ONR, 7/96 – 3/99

This project explores the synthesis of III-N semiconductors and their alloys using a novel metastable growth process. The goal is to develop a fundamental understanding of the issues involved in producing novel, ultra-high-efficiency III-N devices operating in the blue-to-ultraviolet spectral region. Extensive modeling and characterization of the electronic properties of the material is performed in conjunction with thin-film growth.

Investigation of the Thermodynamic and Kinetic Factors Involved in Synthesis of III-N Thin
Films

Principal Investigator: N. Newman

Sponsor: ONR, 11/98 – 3/02

This work is an extension of the above project. It is aimed at the optimization of AlN and its alloys for optoelectronic applications in the ultraviolet spectral region.

Development of Improved Adhesion of Silicone Encapsulants to High-Voltage Microelectronic
Packages

Principal Investigator: N. Newman

Sponsor: Northrop-Grumman Corp., 8/97 – 8/98

Optimization of packaging methods for microwave power modules are being explored. Extensive surface analytical work is used in conjunction with mechanical testing to develop a fundamental understanding of interfacial bonding at ceramic / encapsulation interfaces.

Fabrication of Substrate Heater Compatible with High Temperature, Reactive Gas and
Vacuum Environments

Principal Investigator: N. Newman

Sponsor: Thermionics Labs, Inc., 2/97 – 6/99

Novel instrumentation is being developed for the demanding requirements of reactive growth. This equipment is being designed for applications in the synthesis of electronic materials such as semiconductorsööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööInvestigator: M. ööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööööThis is the first kind of experimental study on this new type of potentially very important material.

Metalorganic Chemical Vapor Deposition of GaN, AlN, and AlGaN Films for UV Detector
Applications (with AASERT Program augmentation)

Principal Investigator: M. Razeghi

Sponsor: ONR, 6/95 – 5/98

InGaN–AlGaN alloys will be some of the most technologically important materials of the next century. Applications will include bright, large, full-color displays; low-cost color laser printers and photocopiers; and high-density optical storage. However, the physics and engineering issues related to experimental realization of optoelectronic devices based on these materials are far from being understood. The purpose of this research is to develop physical models related to experimental realization of ultraviolet detectors based on GaN, AlN, and AlGaN materials using a state-of-the-art semiconductor technology, the MOCVD growth technique. High-speed, high-resistivity GaN p-i-n photodiodes and AlGaN photoconductors are demonstrated based on this newly-developed physical understanding and technique. These have a maximum operating frequency of 98 GHz and a wide range of detection wavelengths as short as l = 200 nm, a record.

GaAs – GaInP Superlattices for Intersubband Photodetection

Principal Investigator: M. Razeghi

Sponsor: Air Force Office of Scientific Research (AFOSR) AASERT Program, 6/95 – 5/98

Quantum-well infrared photodetectors (QWIP’s) based on the GaAs–GaInP material system are excellent candidates for long-wavelength infrared focal-plane arrays (FPA’s) in the 3–20 m m wavelength range. We developed an extensive mathematical modeling using band theory and
spin-orbit interactions. Using the modeling, we demonstrated for the first time high-performance QWIP devices with high valance intersubband absorption in this material system.

Investigation of III-Nitride Alloys for UV Photodetectors and Blue-Green Lasers

Principal Investigator: M. Razeghi

Sponsor: ONR AASERT Program, 6/98 – 5/01

The physical processes of how lasing takes place in InGaN material systems are not fully understood. This project studies the physical origin of the radiative-recombination process in GaN, AlN, and AlGaN III-V nitrides alloys in both theory and experiment. Model calculations are performed for optical gain and luminescence emission in TE and TM polarization with strain and quantum-size effects. Based on this newly-developed physical understanding, high-speed, high-resistivity GaN
p-i-n photodiodes and AlGaN photoconductors are demonstrated up to a maximum operating frequency of 98 GHz and a wide range of detection wavelengths as short as l = 200 nm, a record.

Development of Sb-Based Laser Diode Structures Operating in the 2-5 and 7-9 µm Range

Principal Investigator: M. Razeghi

Sponsor: DARPA AASERT Program, 7/95 – 7/98

Using modeling and state-of-the-art process techniques, this project develops InAsSb / InPAsSb / (AlAsSb) double-heterostructure and multiple-quantum-well lasers for emission wavelengths of 2–5 and 7–9 mm. These lasers have a wide range of civilian and defense applications. Record high output power in both pulsed and continuous-wave modes, wide wavelength coverage, and near-room-temperature operation have been demonstrated.

Semiconductor Laser for 2-5 µm and 7-9 µm Region / Quantum Cascade Lasers

Principal Investigator: M. Razeghi

Sponsor: DARPA / U.S. Army, 8/95 – 4/99

The quantum cascade laser is a novel semiconductor device based on electronic radiative transition between subbands within quantum wells. This laser can be used for long-wavelength emission
(l = 3–20 mm). However, device fabrication requires realizing atomic-scale semiconductor layers with angstrom resolution. This project develops a design model and experimentally realizes such lasers using a state-of-the-art semiconductor technology involving a single-step growth process based on the gas-source molecular-beam epitaxy technique. For the first time, room-temperature operation is demonstrated with a maximum optical output power up to 0.5 W.

MBE Growth of InSb and Related Alloys for Infrared Detection

Principal Investigator: M. Razeghi

Sponsor: DARPA / U.S. Army AASERT Program, 6/96 – 5/99

Uncooled infrared photon detectors are in great demand for applications such as missile detection / situational awareness. Using the novel technique of non-equilibrium mode devices,
we demonstrated the world’s first InAsSb / InAlSb double-heterostructure detectors with the highest reported detectivity at 7m m at room temperature.

Development of III-Nitride Technology for Optoelectronic Devices

Principal Investigator: M. Razeghi

Sponsor: DARPA / ONR, 5/96 – 4/99

The use of GaN, InGaN, and AlGaN materials for optoelectronic devices requires a number of novel technologies. This project investigates several aspects of optimized device design and fabrication methods including: thermal instability of InGaN; p-doping of GaN and AlGaN; and the ECR reactive-ion etching technique. Based on the new understanding developed in this study, high-brightness InGaN / GaN LED’s and CW-operating InGaN / GaN lasers are demonstrated.

Film Growth and Device Fabrication of Visible LED’s and Semiconductor Lasers

Principal Investigator: M. Razeghi

Sponsor: ONR AASERT Program, 6/96 – 5/99

Growth of high-quality InGaN is difficult to achieve. This is because In has a low melting point
relative to the 700˚C temperature where high-quality InGaN is obtained. In fact, the incorporation
of In on InGaN depends critically on temperature. Spatial or temporal temperature fluctuations can cause detrimental spatial inhomogeneity of InGaN. This project studies the mechanisms of how temperature and growth conditions affect In incorporation on InGaN. The existence of quantum-
dot-like structures caused by In spatial inhomogeneity is studied using microscopic electro-luminescence.

GaIn(As)P–GaAs Very-Long-Wavelength Quantum-Well Infrared Photodetectors

Principal Investigator: M. Razeghi

Sponsor: AFOSR, 7/97 – 6/00

Infrared imaging in the very-long-wavelength range is essential in many space and defense applications. This project demonstrates very-long-wavelength InGaAlAs / InP QWIP’s operating in the 13–19 m m infrared range with very sharp spectral width Dl/lof only 10%.

Fabrication and Characterization of AlGaN UV Solar-Blind Photodetectors

Principal Investigator: M. Razeghi

Sponsor: ONR AASERT Program, 6/97 – 5/00

Detection of small ultraviolet signals without interference by ambient sunlight is very important in defense applications such as flame detection and missile countermeasures. AlGaN alloys are ideal for solar-blind photodetectors since they have high rejection ratios against ambient visible light.
This project demonstrates solar-blind AlGaN ultraviolet detectors having rejection ratios of 106,
the highest ever reported.

Demonstration of Uncooled InAsSb Photodetectors for Military Sensors

Principal Investigator: M. Razeghi

Sponsor: DARPA / ONR, 6/97 – 5/00

InAsSb alloys have the lowest bandgaps among technically available III-V compound materials.
These materials can be used for long-wavelength infrared detection (l > 10 mm). Device structures for room-temperature or near-room-temperature operation are developed and fabricated using the MOCVD technique. This project is one of the first experimental demonstrations of these materials for
long-wavelength photodetection applications in an uncooled environment.

Growth and Fabrication of Multi-Quantum Well Infrared Photodetectors

Principal Investigator: M. Razeghi

Sponsor: AFOSR AASERT Program, 6/97 – 5/00

Multi-spectral infrared focal-plane arrays (FPA’s) are needed for applications such as advanced infrared targeting and tracking, nonmetallic land-mine detection, and noninvasive medical diagnosis. This project demonstrates the first two-color, voltage-tunable, InGaAs / InAlAs and InGaAs / InP QWIP’s at 4 m m and 8 m m on low-cost InP substrates.

High Resolution X-Ray Diffractometer

Principal Investigator: M. Razeghi

Sponsor: ONR DURIP Program, 3/98 – 3/99

Stresses are generated during the growth of epitaxial layers of InGaN, AlGaN, InAsSb, and InTlSb alloys on mismatched substrates. This project uses a high-resolution X-ray diffractometer to
study the mechanical and structural properties of these materials via the X-ray reciprocal-
mapping technique. The results are used as feedback to optimize the growth conditions of these materials.

Large Area Lateral Epitaxial Overgrowth of GaN on Si

Principal Investigator: M. Razeghi

Sponsor: ONR, 4/98 – 3/99

Techniques to grow GaN on Si substrates can significantly benefit UV optoelectronic systems by greatly decreasing the packaging cost and increasing reliability. Lateral epitaxial overgrowth is a novel technique to grow GaN on lattice-mismatched substrates. This project uses this technique to achieve large-area growth of GaN particularly on Si substrates. High-quality epilayers are achieved with high lateral-to-vertical aspect ratios and very-low dislocation densities.

International Symposium on the Physics of Semiconductors (Seoul, Korea)

Principal Investigator: M. Razeghi

Sponsor: ONR, 8/98 – 1/99

The project sponsors the organization and administration of an international symposium held in Korea on the physics of semiconductors.

Fellowship: Development of AlGaN UV Photodetectors

Principal Investigator: M. Razeghi

Sponsor: National Aeronautics and Space Administration (NASA) Goddard Space Flight Center,
7/97 – 6/99

This fellowship supports a graduate student studying the development of AlGaN ultraviolet photodetectors. The research includes optimized etching and metal-contact techniques on these hard-to-fabricate materials. High-speed metal-semiconductor-metal photodetectors are demonstrated with maximum operating frequencies up to 92 GHz.

Growth of Antimonide-Based Quantum Wells

Principal Investigator: M. Razeghi

Sponsor: Universal Technology Corp., 5/96 – 12/97

This project is aimed at improving device models and optimizing growth techniques for multiple-quantum-well lasers suitable for high-temperature and wide-spectrum operation. Very-efficient
high-power devices having emission wavelengths covering the mid-infrared range are developed.
The possibility of room-temperature operation is shown.

Investigation of an Approach to Create Shallow Acceptor Levels in III-V Nitrides

Principal Investigator: M. Razeghi

Sponsor: Avyd Devices, Inc., 12/96 – 10/97

Creating shallow acceptor levels in III-V nitrides is one of the most important challenges in the study of GaN-based visible and ultraviolet optoelectronic devices. This project involves optical and electrical characterization of such materials. P-type doping in GaN is achieved using optimized growth conditions identified in this study. This leads to realization of visible high-brightness LED’s and lasers.

Atomic-Force Microscope

Principal Investigator: M. Razeghi

Sponsor: Picolight, Inc., 3/98 – 3/99

This project uses an atomic-force microscope to study the surface states of high-quality GaAs, GaInAs, and Sb-based materials. In particular, structural information about quantum dots created on InGaAs / GaAs is obtained. This information is used in optimizing the growth method for creating high-quality quantum dots.

Demonstration of 1.3 µm Patterned VCSEL

Principal Investigator: M. Razeghi

Sponsor: Picolight, Inc., 4/98 – 5/99

The vertical-cavity surface-emitting laser (VCSEL) for emission at 1.3 mm is one of the most important components in low-cost and high-capacity optical communications technology. Previously, VCSEL’s were fabricated on InP substrates. However, InP techniques are less developed than Si or GaAs. This project develops VCSEL’s on GaAs substrates using a novel patterned-substrate approach. This permits mature GaAs technology to be used, allowing the integration of VCSEL’s with detectors, amplifiers, etc. The project also addresses fundamental device-fabrication issues such as etching of patterned substrates and localized epitaxial growth of semiconductors.

Bandgap-Engineered Heterojunction Internal Photoemission Detector

Principal Investigator: M. Razeghi

Sponsor: Solid-State Scientific Corp., 8/98 – 12/98

The silicide-based infrared focal-plane array (FPA) is currently the primary device used for IR imaging since it is highly compatible with silicon technology. However, due to the short carrier lifetime in the silicides, the device efficiency is only about 1%. This project demonstrates high-quality films of InAsSb on Si substrates which can replace silicide thin films and significantly improve device efficiency.

GaInP / InGaAs / GaAs MODFET (Modulation-Doped Field-Effect Transistors)

Principal Investigator: M. Razeghi

Sponsor: Middle East Technical University (Turkey), 6/95 – 12/97

This project aims at the growth and characterization of Al-free GaInP / InGaAs / GaAs hetero-structures for modulation-doped field-effect transistors. The Al-free structure has potentially important advantages compared to the conventional AlGaAs / InGaAs / GaAs structure because of the absence of X-center defects and a higher valence bandgap offset. This study includes extensive device modeling based on Monte Carlo simulations, and comparisons with experimental results.

Book Sections and Chapters1

N. Newman,* "Thermochemistry of III-N Semiconductors," in Semiconductors and Semimetals:
III-Nitrides, J. Pankove and T. D. Moustakas, eds., New York: Academic Press, 1998.

M. Razeghi,* A. Saxler, P. Kung, D. Walker, X. Zhang, K. S. Kim, H. R. Vydyanath, J. Solomon,
M. Ahoujja, and W. C. Mitchel, "New developments in III-nitride material and device applications,"
pp. 277–284 in Physics of Semiconductor Devices, Vol. 1, V. Kumar and S. K. Agarwal, eds.,
New Delhi, India: Narosa Publishing, 1998.

M. Razeghi,* "Infrared photodetectors and imaging arrays using advanced III-V materials,"
pp. 746–753 in Physics of Semiconductor Devices, Vol. 2, V. Kumar and S. K. Agarwal, eds.,
New Delhi, India: Narosa Publishing, 1998.

Journal Papers1

K.-W. Chang, B. W. Wessels, D. B. Studebaker, T. J. Marks, J. L. Schindler, C. R. Kannewurf,*
M. Aprili, and L. Green, "Growth and properties of Sr2CuO2(CO3) thin films prepared from metal-
organic chemical vapor deposition-derived precursor films," Physica C, vol. 291, pp. 242–248,
1997.

D.-Y. Chung, K.-S. Choi, L. Iordanidis, J. L. Schindler, P. W. Brazis, C. R. Kannewurf,* B. Chen,
S. Hu, C. Uher, and M. G. Kanatzidis, "High thermopower and low thermal conductivity in
semiconducting ternary K-Bi-Se compounds: Synthesis and properties of b -K2Bi8Se13 and
K2.5Bi8.5Se14 and their Sb analogues," Chemistry of Materials, vol. 9, pp. 3060–3071, 1997.

F. H. Kaatz, P. R. Markworth, J.-Y. Dai, D. B. Buchholz, X. Liu, M. P. Chudzik, J. A. Belot,
C. R. Kannewurf,* T. J. Marks, and R. P. H. Chang, "Stability of bilayer films of YBa2Cu3O7 and
Y-ZrO2 grown on LaAlO3 by pulsed organometallic beam epitaxy, Chemical Vapor Deposition,
vol. 4, pp. 99–102, 1998.

R. J. McNeely, J. A. Belot, B. J. Hinds, T. J. Marks, J. L. Schindler, M. P. Chudzik, and
C. R. Kannewurf,* "Efficient route to TlBa2Ca2Cu3O9+x thin films by metal-organic chemical vapor
deposition using TIF as a thallination source," Applied Physics Lett., vol. 71, pp. 1243–1245,
1997.

_______

1All citations are listed in the alphabetical order of the Group faculty member(s), denoted by a *.

R. J. McNeely, J. A. Belot, J. L. Schindler, M. P. Chudzik, C. R. Kannewurf,* X. F. Zhang, D. J. Miller,
and T. J. Marks, "Novel metal-organic chemical vapor deposition / TIF annealing route to thin
films of Tl1Ba2Ca2Cu3O9+x," J. Superconductivity, vol. 11, pp. 133–134, 1998.

T. Moriga, D. D. Edwards, T. O. Mason, G. B. Palmer, K. R. Poeppelmeier, J. L. Schindler,
C. R. Kannewurf,* and I. Nakabayashi, "Phase relationships and physical properties of
homologous compounds in the zinc oxide-indium oxide system," J. American Ceramic Society,
vol. 81, pp. 1310–1316, 1998.

R. Patschke, J. Heising, M. Kanatzidis, P. Brazis, and C. R. Kannewurf,* "KCuCeTe4: A new
intergrowth rare earth telluride with an incommensurate superstructure associated with a distorted
square net of tellurium," Chemistry of Materials, vol. 10, pp. 695–697, 1998.

R. Patschke, J. Heising, J. Schindler, C. R. Kannewurf,* and M. Kanatzidis, "Side occupancy wave
and unprecedented infinite zigzag (Te22)n chains in the flat Tc nets of the new ternary rare earth
telluride family AlIn3Te8," J. Solid State Chemistry, vol. 135, pp. 111–115, 1998.

D. B. Studebaker, J. Zhang, T. J. Marks, Y. Y. Wang, V. P. Dravid, J. Schindler, and
C. R. Kannewurf,* "Liquid source metal-organic chemical-vapor deposition of high-quality
YBa2Cu3O7x films on polycrystalline silver substrates," Applied Physics Lett., vol. 72,
pp. 1253–1255, 1998.

A. Wang, J. Dai, J. Cheng, M. P. Chudzik, T. J. Marks, R. P. H. Chang, and C. R. Kannewurf,*
"Charge transport, optical transparency, microstructive, and processing relationships in
transparent conductive indium-zinc oxide films grown by low-pressure metal-organic chemical
vapor deposition," Applied Physics Lett., vol. 73, pp. 327–329, 1998.

Z. Y. Fan and N. Newman,* "Precise control of atomic nitrogen production in an ECR plasma using
N2 / noble gas mixtures," Applied Physics Lett., vol. 73, p. 456, 1998.

Z. Y. Fan and N. Newman,* "Kinetic energy distribution of nitrogen ions in an electron cyclotron
resonance (ECR) plasma," J. Vacuum Sci. Technol., vol. A16, p. 2132 , 1998.

G. S. Sudhir, H. Fujii, W. S. Wong, C. Kisielowski, N. Newman,* C. Dieker, Z. Liliental Weber,
M. R. Rubin and E. R. Weber, "Control of the structure and surface morphology of gallium nitride
and aluminum nitride thin films by nitrogen background pressure in pulsed laser deposition,"
J. Electronic Materials, vol. 27, p. 215, 1998.

G. S. Sudhir, H. Fujii, W. S. Wong, C. Kisielowski, N. Newman,* C. Dieker, Z. Liliental Weber,
M. R. Rubin and E. R. Weber, "Pulsed laser deposition of aluminum nitride and gallium nitride thin
films," Appl. Surface Science, vol. 127-9, p. 471, 1998.

M. Razeghi,* "The Center for Quantum Devices — Extending the scope of photonics," III-V Review,
vol. 10, pp. 36–43, Oct. 1997.

M. Razeghi* and Y. Yi, "High-power Al-free InGaAsP / GaAs near-infrared semiconductor lasers,"
Optoelectronics Review, vol. 6, no. 2, pp. 81–92, 1998.

C. Besikci, Y. Civan, S. Ozder, O. Sen, C. Jelen, S. Slivken, and M. Razeghi,* "Gas source molecular
beam epitaxy growth and characterization of Ga0.51In0.49P / InxGa1-xAs / GaAs modulation-doped
field-effect transistor structures," Semiconductor Science Technology, vol. 12, pp. 1472–1478,
Nov. 1997.

J. Diaz, H. Yi, and M. Razeghi,* "Long-term reliability of Al-free InGaAsP / GaAs (l = 808-nm) lasers
at high-power, high-temperature operation," Applied Physics Lett., vol. 71, pp. 3042–3044,
Nov. 24, 1997.

C. Jelen, S. Slivken, T. David, and M. Razeghi,* "Noise performance of InGaAs / InP quantum well
infrared photodetectors," IEEE J. Quantum Electronics, vol. 34, pp. 1124-1128, July 1998.

T. Kato, P. Kung, A. Saxler, C.-J. Sun, H. Ohsato, M. Razeghi,* and T. Okuda, "Simultaneous growth
of two differently oriented GaN epilayers on (11.0) sapphire: II. A growth model of (00.1) and
(10.0) GaN," J. Crystal Growth, vol. 183, pp. 131–139, Jan. 1, 1998.

S. Kim, H. Mohseni, M. Erdtmann, E. Michel, C. Jelen, and M. Razeghi,* "Growth and
characterization of InGaAs / InGaP quantum dots for mid-infrared photoconductive detector,"
Applied Physics Lett., vol. 73, pp. 963–965, Aug. 17, 1998.

P. Kung, A. Saxler, D. Walker, A. Rybaltowski, X. Zhang, J. Diaz, and M. Razeghi,* "GaInN / GaN
multi-quantum well laser diodes grown by low-pressure metalorganic chemical vapor deposition,"
MRS Internet Journal of Nitride Semiconductor Research, vol. 3, no. 1, Jan. 14, 1998.

P. Kung, X. Zhang, A. Saxler, D. Walker, M. Razeghi,* W. Qian, and V. P. Dravid, "MOCVD growth of
high quality GaN-AlGaN based structures on Al2O3 substrates with dislocation density less than
107 cm-2," J European Ceramics Society, vol. 17, pp. 1781–1785, 1997.

J. J. Lee, J. D. Kim, and M. Razeghi,* "Long-wavelength infrared photodetectors based on InSbBi
grown on GaAs substrates," Applied Physics Lett., vol. 71, pp. 2298–2300, Oct. 20, 1997.

J. J. Lee, J. D. Kim, and M. Razeghi,* "Room temperature operation of 8-12 mm InSbBi infrared
photodetectors on GaAs substrates," Applied Physics Lett., vol. 73, pp. 602–604, Aug. 3, 1998.

J. J. Lee and M. Razeghi,* "Exploration of InSbBi for uncooled long-wavelength infrared
photodetectors," Optoelectronics Review, vol. 6, no. 1, pp. 25–36, 1998.

E. Michel and M. Razeghi,* "Recent advances in Sb-based materials for uncooled infrared
photodetectors," Optoelectronics Review, vol. 6, no. 1, pp. 11–23, 1998.

H. Mohseni, E. Michel, J. Sandven, M. Razeghi,* W. Mitchel, and G. Brown, "Growth and
characterization of InAs / GaSb photoconductors for long wavelength infrared range," Applied
Physics Lett., vol. 71, pp. 1403–1405, Sept. 8, 1997.

A. Rybaltowski, Y. Xiao, D. Wu, B. Lane, H. Yi, H. Feng, J. Diaz, and M. Razeghi,* "High power
InAsSb / InPAsSb / InAs mid-infrared lasers," Applied Physics Lett., vol. 71, pp. 2430–2432,
Oct. 27, 1997.

A. Saxler, D. Walker, P. Kung, X. Zhang, M. Razeghi,* J. Solomon, W. C. Mitchel, and H. R.
Vydyanath, "Comparison of trimethygallium and triethygallium for the growth of GaN," Applied
Physics Lett., vol. 71, pp. 3272–3274, Dec. 1, 1997.

S. Slivken, C. Jelen, A. Rybaltowski, J. Diaz, and M. Razeghi,* "Gas-source molecular beam epitaxy
growth of 8.5 mm quantum cascade laser," Applied Physics Lett., vol. 71, pp. 2593–2595, Nov. 3,
1997.

D. Walker, A. Saxler, P. Kung, X. Zhang, M. Hamilton, J. Diaz, and M. Razeghi,* "Visible blind GaN
p-i-n photodiodes," Applied Physics Lett., vol. 72, pp. 3303–3305, June 22, 1998.

Symposium Papers1

D.-Y. Chung, T. Hogan, J. Schindler, L. Iordanidis, P. Brazis, C. R. Kannewurf,* B. Chen, C. Uher,
and M. G. Kanatzidis, "Searching for new thermoelectrics in chemically and structurally complex
bismuth chalcogenides," Thermoelectric Materials—New Directions and Approaches, T. M. Tritt,
M. G. Kanatzidis, H. B. Lyon, Jr., and G. D. Mahan, eds., Materials Research Soc. Symp. Proc.,
vol. 478 (Materials Research Soc., Pittsburgh 1997), pp. 333–344.

D.-Y. Chung, T. Hogan, J. Schindler, L. Iordanidis, P. Brazis, C. R. Kannewurf,* B. Chen, C. Uher,
and M. G. Kanatzidis, "Complex bismuth chalcogenides as thermoelectrics," Proc. 16th Int’l. Conf.
on Thermoelectrics, Int’l. Thermoelectric Soc. (IEEE, Piscataway, NJ, 1998), pp. 459–462.

G. B. Palmer, K. R. Poeppelmeier, D. D. Edwards, T. Moriga, T. O. Mason, J .L. Schindler, and
C. R. Kannewurf,* "Phase equilibria and properties of transparent conductors in the indium-tin-
zinc oxide system," Flat Panel Display Materials III, R. T. Fulks, G. N. Parsons, D. E. Slobodin,
and T. H. Yuzurika, eds., Materials Research Soc. Symp. Proc., vol. 471 (Materials Research
Soc., Pittsburgh 1997), pp. 93–98.

J. L. Schindler, T. P. Hogan, P .W. Brazis, C. R. Kannewurf,* D.-Y. Chung, and M. G. Kanatzidis,
"Electrical properties and figures of merit for new chalcogenide-based thermoelectric materials,"
Thermoelectric Materials—New Directions and Approaches, T. M. Tritt, M .G. Kanatzidis, H. B.
Lyon, Jr., and G. D. Mahan, eds., Materials Research Soc. Symp. Proc., vol. 478 (Materials
Research Soc., Pittsburgh 1997), pp. 327–332.

X. Yao, S. Ehrlich, G. Liedl, T. Hogan, C. R. Kannewurf,* and J. M. Honig, "Electron transport in
NiS2-xSex crystals," Solid-State Chemistry of Inorganic Materials, P. K. Davies, A. J. Jacobson,
C. C. Torardi, and T. A. Vanderak, eds., Materials Research Soc. Symp. Proc., vol. 453
(Materials Research Soc., Pittsburgh 1997), pp. 291–303.

M. Razeghi,* "Reliable high-power uncoated Al-free InGaAsP / GaAs lasers for cost-sensitive optical
communication and processing applications," SPIE Conf. Proc., Dallas, TX, Nov. 4–5, 1997,
vol. 3234, pp. 125–133.

M. Erdtmann, S. Kim, and M. Razeghi,* "Localized epitaxy for vertical cavity surface emitting laser
applications," Materials Science Forum Proc., Aveiro, Portugal, July 1997, vol. 258–263,
pp. 1637–1642.

C. Jelen and M. Razeghi,* "InP-based multi-spectral quantum well infrared photodetectors,"
Int’l. Semiconductor Device Research Symp. (ISDRS ‘97) Proc., Charlottesville, VA , Dec. 11–13,
1997, pp. 599–602.

C. Jelen, S. Slivken, T. David, G. Brown, and M. Razeghi,* "Responsivity and noise performance of
InGaAs / InP quantum well infrared photodetectors," SPIE Conf. Proc., San Jose, CA, Jan. 28–30,
1998, vol. 3287, pp. 96–104.

S. Kim, M. Erdtmann, and M. Razeghi,* "The long-wavelength luminescence observation from the
self-organized InGaAs quantum dots grown on (100) GaAs substrate by metallorganic chemical
vapor deposition," Materials Science Forum Proc., Aveiro, Portugal, July 1997, vol. 258–263,
pp. 1643–1652.

P. Kung, X. Zhang, D. Walker, A. Saxler, and M. Razeghi,* "GaN p-i-n photodiodes with high visible-
to-ultraviolet rejection ratio," SPIE Conf. Proc., San Jose, CA, Jan. 28–30, 1998, vol. 3287,
pp. 214–220.

H. J. Lee, M. G. Cheong, E. K. Suh, and M. Razeghi,* "Electrical transport properties of highly doped
N-type GaN epilayers," SPIE Conf. Proc., San Jose, CA, Jan. 28–30, 1998, vol. 3287,
pp. 321–326.

H. Mohseni, E. Michel, W. Mitchel, G. Brown, and M. Razeghi,* "Growth and characterization of
InAs / GaSb type II superlattices for long-wavelength infrared detectors," SPIE Conf. Proc.,
San Jose, CA, Jan. 28–30, 1998, vol. 3287, pp. 30–37.

A. Rogaski and M. Razeghi,* "Narrow gap semiconductor photodiodes," SPIE Conf. Proc., San Jose,
CA, Jan. 28–30, 1998, vol. 3287, pp. 2–13.

A. Saxler, K. S. Kim, D. Walker, P. Kung, X. Zhang, G. J. Brown, W. C. Mitchel, and
M. Razeghi,* "Electroluminescence of III-nitride double heterostructure light-emitting diodes with
silicon and magnesium doped InGaN, Materials Science Forum Proc., Aveiro, Portugal,
July 1997, vol. 258–263, pp. 1229–1234.

A. Saxler, P. Kung, X. Zhang, D. Walker, J. Solomon, M. Ahoujja, W. C. Mitchel, H. R. Vydyanath,
and M. Razeghi,* "GaN doped with sulfur," Materials Science Forum Proc., Aveiro, Portugal,
July 1997, vol. 258–263, pp. 1161–1166.

A. Saxler, P. Kung, X. Zhang, D. Walker, J. Solomon, W. C. Mitchel, and M. Razeghi,* "GaN grown
using trimethygallium and triethygallium," Materials Science Forum Proc., Aveiro, Portugal,
July 1997, vol. 258–263, pp. 1081–1086.

S. Slivken and M. Razeghi,* "Mid-infrared quantum cascade lasers grown by gas-source molecular
beam epitaxy," Int’l. Semiconductor Device Research Symp. (ISDRS ‘97) Proc., Charlottesville,
VA , Dec. 11–13, 1997, pp. 607–610.

S. Slivken and M. Razeghi,* "8.5-µm room-temperature quantum cascade lasers grown by gas-
source molecular beam epitaxy," SPIE Conf. Proc., San Jose, CA, Jan. 28–30, 1998, vol. 3287,
pp. 314–321.

M. Tadic, C. Jelen, S. Slivken, and M. Razeghi,* "Photoresponse of InGaAsP-based p-doped
quantum well infrared photodetectors," 21st Int’l. Conf. on Microelectronics (MIEL’97) Proc.,
Yugoslavia, Sept. 14–17, 1997, vol. 1, pp. 315–318.

M. Tadic, C. Jelen, S. Slivken, and M. Razeghi,* "In-plane electron dynamics and hot-electron effects
in a quantum cascade laser," 21st Int’l. Conf. on Microelectronics (MIEL’97) Proc., Yugoslavia,
Sept. 14–17, 1997, vol. 1, p.319–322.

Invited Talks and Seminars1

N. Newman,* "Kinetic barriers to surface reactions: Their critical role in meta-stable III-N growth,"
Focus Session, 25th Conf. on Physics and Chemistry of Semiconductor Interfaces, Salt Lake
City, UT, Jan. 19, 1998.

N. Newman,* "Kinetic energy distribution of activated nitrogen in an electron cyclotron resonance
(ECR) plasma," 3rd Annual ONR Workshop on Selected Energy Epitaxy of Wide Bandgap
Semiconductors (SEE-3), Arizona State University, Tempe, Arizona, Jan. 23, 1998.

N. Newman,* "MBE growth under metastable conditions," Chemical Engineering Dept. Colloquium,
Case Western Reserve University, Cleveland, OH, Feb. 26, 1998.

M. Razeghi,* "Sb-based infrared materials for uncooled photodetector applications," 5th Int’l. Symp.
on Long-Wavelength Infrared Detectors and Arrays — Physics and Applications, Paris, France,
Aug. 31–Sept. 5, 1997.

M. Razeghi,* "Reliable high-power uncoated Al-free InGaAsP / GaAs lasers for cost-sensitive optical
communication and processing applications," SPIE Conf., Design and Manufacturing of WDM
Devices, Dallas, TX, Nov. 4–5, 1997.

M. Razeghi,* "Trends in optoelectronics," Conf. on Gallium Arsenide & Other Compound
Semiconductors, San Diego, CA, Nov. 12–14, 1997.

M. Razeghi,* "Infrared photodetectors and imaging arrays using advanced III-V materials,"
9th Int’l. Workshop on Physics of Semiconductor Devices (IWPSD), New Delhi, India,
Dec. 16–20, 1997.

M. Razeghi,* "New developments in III-nitride material and device applications," 9th Int’l. Workshop
on Physics of Semiconductor Devices (IWPSD), New Delhi, India, Dec. 16–20, 1997.

M. Razeghi,* "Narrow-gap semiconductor photodiodes," SPIE Photonics West ‘98, Photodetectors:
Materials and Devices II, San Jose, CA, Jan. 24–30, 1998.

M. Razeghi,* "Multiple-quantum-well structures for multicolor infrared detectors," SPIE Photonics
West ‘98, Photodetectors: Materials and Devices II, San Jose, CA, Jan. 24–30, 1998.

M. Razeghi,* "8.5-µm room-temperature quantum cascade lasers grown by gas-source molecular
beam epitaxy," SPIE Photonics West ‘98, Integrated Optic Devices II, San Jose, CA, Jan. 24–30,
1998.

M. Razeghi,* "Continuous-wave room temperature operation of InGaN / GaN multi-quantum well
lasers grown by low-pressure metallorganic chemical vapor deposition," SPIE Photonics West
‘98, In-Plane Semiconductor Lasers, San Jose, CA, Jan. 24–30, 1998.

M. Razeghi,* "Low-threshold aluminum-free GaInN / GaN multi-quantum-well blue lasers: Material
growth, characterization, device fabrication, and testing," Cornell University, Ithaca, NY, March
10, 1998.

M. Razeghi,* "21st century: The final frontier for III-nitride materials and devices," Future Trends in
Microelectronics, Ile des Embiez, France, May 31–June 5, 1998.

M. Razeghi, "Exploration of the entire spectrum of III-V semiconductors for opto-electronics,"
23rd Int’l. Summer College on Physics and Contemporary Needs, Bhurban, Pakistan,
June 26–July 5, 1998.

Symposium Sessions Organized / Chaired1

M. Razeghi,* session co-chair, "Photodetectors: Materials and Devices III," at SPIE Photonics West
'98, San Jose, CA, Jan. 24–30, 1998.

M. Razeghi,* program committee, "Integrated Optic Devices II," at SPIE Photonics West '98,
San Jose, CA, Jan. 24–30, 1998.

Patents Issued1

M. Razeghi,* U.S. Patent 5,668,395, Composition for InSb and GaAs Thin Film on Silicon Substrate
for Use in Photodetectors and Method for Making InSb p-i-n Photodetector on Si Substrate Using
InSb Doped 5 x 10 Buffer Layer in Order to Decrease Dark Current of PD, Sept. 16, 1997.

M. Razeghi,* U.S. Patent 5,726,078, Buried-Ridge Laser Device Emitting at 0.78 µm up to 10 µm,
March 10, 1998.

Ph.D. Dissertations1

C. Jelen, GaInAsP-Based N-Type QWIP Photodetectors: Growth, Characterization, and Fabrication,
June 1998. (M. Razeghi*)

A. Saxler, Exploration of LP-MOCVD Grown III- Nitrides on Various Substrates, June 1998.
(M. Razeghi*)

H.-J. Yi, Modeling and Analysis of Al-Free Near and Mid-Infrared Semiconductor Lasers, June 1998.
(M. Razeghi*)