Harry Hier - Academia.edu (original) (raw)

Papers by Harry Hier

: A novel technique is used to determine the minority carrier lifetimes, interface recombination ... more : A novel technique is used to determine the minority carrier lifetimes, interface recombination velocity, and radiative recombination constant from time-resolved photoluminescence measurements on a set of 3 molecular beam epitaxy (MBE)-grown gallium arsenide (GaAs)/aluminum gallium arsenide (AlGaAs) double heterostructures (DHs) and published theory. This technique is used to determine that a distributed Bragg reflector between the substrate and the DHs increases the GaAs nonradiative lifetime. The fractional increase in the nonradiative lifetime varies with the MBE growth parameters.

MRS Advances, 2019

Recent progress in semiconductor materials with minor nonradiative recombination has stimulated i... more Recent progress in semiconductor materials with minor nonradiative recombination has stimulated investigations of novel photovoltaic (PV) converters with optical control of radiative emission. Angle restricted emission was experimentally demonstrated in PV devices with external photon recycling due to specific photonic crystals or mirrors. In this work we investigate the power beam conversion by the cell with front “greenhouse” filter, which transmits the laser light, but recycles the low energy bandgap quanta emitted by the semiconductor cell. We calculate the limiting characteristics of the greenhouse PV converters and optimize design of the converter taking into account the nonradiative recombination processes. In optimized devices addition of the greenhouse filter can increase power beam conversion efficiency by several percent.

International Technical Digest on Electron Devices

Summary form only given. The authors report the state-of-the-art RF performance of InAlAs/InP MOD... more Summary form only given. The authors report the state-of-the-art RF performance of InAlAs/InP MODFETs, grown for the first time via MBE (molecular beam epitaxy). The S-parameters of the FETs were measured from 0.5 to 26.5 GHz for various bias voltages (both V/sub gs/ and V/sub ds/). Maximum stable gains (MSGs) of 13 and 11.5 dB at 18 and 26.5 GHz, respectively, were measured for a source-drain voltage of 7.0 V. Extrapolating MSG at 6 dB/octave, a maximum oscillation frequency of about 75 GHz is predicted.<<ETX>>

Journal of Electronic Materials, 2014

LEOS 1992 Summer Topical Meeting Digest on Broadband Analog and Digital Optoelectronics, Optical Multiple Access Networks, Integrated Optoelectronics, and Smart Pixels

The authors report the growth and fabrication of a double-heterojunction bipolar transistor (DHBT... more The authors report the growth and fabrication of a double-heterojunction bipolar transistor (DHBT) using the InP/InAlAs material system. The measured Gummel plot exhibits a collector current ideality factor of 1.25 and a base current ideality factor of 1.5. A collector-emitter breakdown voltage of 6.5 V was measured. From the measured S-parameters, the extrapolated current-gain-cut-off frequency for a 5-μm×5-μm size device was 6.5 GHz. The results obtained indicate that the InP/InAlAs heterostructure grown by molecular beam epitaxy is suitable for p-n-p HBTs (heterojunction bipolar transistors)

2003 IEEE Aerospace Conference Proceedings (Cat. No.03TH8652)

This invention describes an approach for monolithically integrating all the components of a photo... more This invention describes an approach for monolithically integrating all the components of a photoreceiver—optical amplifier, optical band-pass filter, and photodiode module—in a single chip. The photoreceiver array employs unique optical amplifier and conversion technologies that provides the ultra-sensitivity required for free space optical communications networks. As an example, by monolithically integrating a vertical cavity surface emitting laser-diode (VCSEL) optical preamplifier with a photodiode receiver and related amplifiers and filters on the same chip, sensitivities as low as −47 dBm (62 photons/bit at 2.5 Gb/s), along with an order of magnitude reduction in size, weight, and power consumption over comparable commercial-off-the-shelf (COTS) components can be demonstrated. In accordance with another aspect of the present invention, the concept of monolithic integration of optical amplifier with photodetector is extended to lasers, another amplifier and modulators covering ultra violet to very long wavelength infrared using the InP, GaAs, GaSb, InAs, InSb, SiGe, SiC and GaN etc based technologies.

Infrared Physics & Technology, 2015

Abstract The addition of nitrogen to III–V alloys has been widely studied as a method of modifyin... more Abstract The addition of nitrogen to III–V alloys has been widely studied as a method of modifying the band gap for mid-infrared (IR) applications. Lattice matching these alloys to convenient substrates such as GaSb, however, is challenging due to the significantly different lattice constants. One approach is to use InGaSbN/InAs grown on GaSb where the InGaSbN layer has a larger lattice constant than the substrate, and the InAs layer has a lower lattice constant, and thus the compressive and tensile stress of the superlattice layers can be balanced in a so called strained-layer superlattice. In this paper, we report InxGa1−xSb1−yNy/InAs strained-layer superlattices with type-II (staggered) energy offsets on GaSb substrates, where the design of the layer thickness is based on the lattice constants and the elastic moduli. Three different strain balance conditions are reported: fixed superlattice period thickness, fixed InAs well thickness, and fixed InxGa1−xSb1−yNy barrier thickness. Eight-band k · p simulations of these structures were used to analyze the superlattice miniband energies. For fully strain balanced InxGa1−xSb1−yNy/InAs superlattices lattice matched to the GaSb substrate, careful consideration of strain balance conditions was needed to achieve a lower effective miniband gap needed for longer cutoff wavelength detectors. For non-strained balanced InxGa1−xSb1−yNy/InAs superlattices, long-wavelength cutoff up to 8 μm can be achieved as part of a trade-off between the deleterious effects of strain and the reduction of the barrier band gap through N incorporation.

SPIE Proceedings, 2012

The optical properties of bulk unrelaxed InAsSb layers having a low temperature photoluminescence... more The optical properties of bulk unrelaxed InAsSb layers having a low temperature photoluminescence (PL) peak up to 10 μm are presented. The materials were grown on GaSb substrates by molecular beam epitaxy. The lattice mismatch between the epilayers ...

SPIE Proceedings, 2007

Epitaxial Technologies has developed a single photon counting photoreceiver that can operate in t... more Epitaxial Technologies has developed a single photon counting photoreceiver that can operate in the linear mode to avoid the drawbacks of Geiger mode detectors. The Company&amp;amp;#x27;s linear single photon counting photoreceiver array technology is based on cascading optical amplifiers on-chip with APDs to enable single photon capability below the APD breakdown voltage through ultra-low noise gain and preamplification. We have

Optical Fiber Communication Conference and National Fiber Optic Engineers Conference, 2009

We report the development of ultrasensitive photoreceivers, based on ultra high gain and low exce... more We report the development of ultrasensitive photoreceivers, based on ultra high gain and low excess noise APDs, with sensitivities of -35.5 dBm at 2.488 Gbps and 10-10 BER and the potential for 6-12 dB sensitivity enhancement at higher bit rates. Current APD devices are not capable of simultaneous high gain and low noise. The developed APD detectors enable the achievement of optimum sensitivity at an order of magnitude higher gain than state-of-the-art detectors. The resulting APD receivers have been produced as ROSAs, fiber-coupled pigtail devices and ITU grid spaced linear arrays.

SPIE Proceedings, 2004

This paper describes the design, growth and fabrication characterization of novel multi-wavelengt... more This paper describes the design, growth and fabrication characterization of novel multi-wavelength QWIP wafers based on InP material systems. We designed, grew, fabricated and characterized AlGaInAs/GaInAs QWIPs suitable for operation at 3-5 μm, and 8-12 μm spectral range. We fabricated mid-wave IR 320 x 250 focal plane arrays, hybridized them with Si -readout circuits and performed radiometric and imaging tests. Excellent imaging results of the mid-wave IR focal plane arrays with an operability of 88% and mean NEDT of 0.09K have been achieved. To our knowledge, this is the first imaging with InP based QWIPs focal plane array.

Advanced Photon Counting Techniques III, 2009

This paper reports the demonstration of single photon counting receivers with pulse detection eff... more This paper reports the demonstration of single photon counting receivers with pulse detection efficiency as high as 68% for 2 photons and single photon counting probabilities as high as 44% at 1550-nm, 1 MHz rate and room temperature and with linear-mode (below the breakdown voltage), high speed response in the 450-1700 nm spectral band. The developed single photon counting receiver is based on Epitaxial Technologies' ultra high gain (>300000), low excess noise, linear-mode APDs, which have been fabricated in dimensions ranging from 25 to 200-μm and array formats up to 32 x 32.

Advanced Photon Counting Techniques II, 2007

We report high gain, high sensitivity 1064-1550 nm avalanche photodiodes (APDs) that are capable ... more We report high gain, high sensitivity 1064-1550 nm avalanche photodiodes (APDs) that are capable of single photon counting in the linear mode below the breakdown voltage and at room temperature. Epitaxial Technologies has developed AlInAs/GaInAs APDs with multiplication gains as high as 347,000, sensitivities of -69 to -77 dBm and photon detection efficiencies as high as 27%. The single photon

Microelectronic Engineering, 1989

Journal of The Electrochemical Society, 1988