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7 Mar 1994

Volume 64, Issue 10, pp. 1177-1308

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Photon counting using a large area avalanche photodiode cooled to 100 K

Nathan G. Woodard, Eric G. Hufstedler, and Gregory P. Lafyatis

Appl. Phys. Lett. 64, 1177 (1994); http://dx.doi.org/10.1063/1.110881 (3 pages) | Cited 12 times

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We have detected single 650 nm photons with quantum efficiencies greater than 60% using a large area silicon avalanche photodiode. We cool a 5 mm diam commercially available device to 100 K and operate in the gain‐mode. For most applications—from the near‐infrared to the ultraviolet—this device is the most sensitive photon counting detector that has ever been demonstrated. In typical photon counting applications, this detector should prove to be between two and one hundred times more sensitive than the best currently available devices.  
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85.60.Dw Photodiodes; phototransistors; photoresistors
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors

Possibility of dc drift reduction of Ti:LiNbO3 modulators via dry O2 annealing process

Hirotoshi Nagata, Junichiro Ichikawa, Masanobu Kobayashi, Jun Hidaka, Hideki Honda, Kazumasa Kiuchi, and Tohru Sugamata

Appl. Phys. Lett. 64, 1180 (1994); http://dx.doi.org/10.1063/1.110882 (3 pages) | Cited 7 times

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The possibility of the dc drift reduction of Ti:LiNbO3 optical modulators via the dry O2 annealing process of the wafer is investigated. In such modulators, the hydrogen impurities are reduced compared against those in the wet O2 annealed ones which exhibit large dc drifts. The dc drifts are observed to be less than 3 V for the dc bias application of 5 V at 80 °C through 60 h, but the dc drift in the second measurement of the same modulator is found to 5 V. After the bias application, the migration of H+ ions are observed in the Ti:LiNbO3.
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42.79.Hp Optical processors, correlators, and modulators
73.50.Dn Low-field transport and mobility; piezoresistance
61.72.up Other materials
81.65.-b Surface treatments

Stress‐optic effect in ice

K. Ravi‐Chandar, B. Adamson, J. Lazo, and J. P. Dempsey

Appl. Phys. Lett. 64, 1183 (1994); http://dx.doi.org/10.1063/1.110883 (3 pages) | Cited 2 times

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It is demonstrated in this letter that single‐crystal ice exhibits stress‐optic effect or temporary stress‐induced birefringence. This effect can be used in the exploration of the stresses using the standard techniques of photoelasticity. The photoelastic sensitivity of ice is quite high compared to glass and thus, should be quite useful in the determination of stresses in polycrystalline materials particularly near grain boundaries and in the vicinity of cracks.
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78.20.Fm Birefringence
42.25.Lc Birefringence
61.72.Mm Grain and twin boundaries

Demonstration of high energy extraction efficiency in a laser‐diode pumped high gain Nd:YAG regenerative amplifier

Kenta Naito, Masato Ohmi, Koji Ishikawa, Masanori Akatsuka, Masanobu Yamanaka, Masahiro Nakatsuka, Sadao Nakai, and Tsuyoshi Sato

Appl. Phys. Lett. 64, 1186 (1994); http://dx.doi.org/10.1063/1.110884 (3 pages) | Cited 1 time

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High energy extraction efficiency of 48±4% for the cavity mode cross section (17.5%±1% for the entire lasant cross section) and high energy gain of 71±1 dB have been demonstrated simultaneously, for the first time, in a laser‐diode pumped Nd:YAG regenerative amplifier (RA). The RA was operated at an initial small‐signal gain of 3.15±0.20, an input pulse energy of 0.5±0.1 nJ (pulse width of 910±12 ps), an amplified output pulse energy of 6.0±0.3 mJ (pulse width <1 ns), and a repetition rate of 50 Hz. The dependence of energy extraction efficiency on initial small‐signal gain of the RA was shown to be well fitted with the theory of Lowdermilk and Murray [J. Appl. Phys. 51, 2436 (1980)].
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.55.Rz Doped-insulator lasers and other solid state lasers

Room‐temperature diode‐pumped continuous‐wave SrY4(SiO4)3O: Yb3+, Er3+ crystal laser at 1554 nm

J. C. Souriau, R. Romero, C. Borel, C. Wyon, C. Li, and R. Moncorgé

Appl. Phys. Lett. 64, 1189 (1994); http://dx.doi.org/10.1063/1.110885 (3 pages) | Cited 25 times

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Continuous‐wave (cw) laser operation at room temperature of an Yb3+, Er3+ doped oxyapatite single crystal SrY4(SiO4)3O pumped at 980 nm by an InGaAs diode laser has been achieved around the eye‐safe laser wavelength of 1554 nm.
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42.55.Rz Doped-insulator lasers and other solid state lasers
42.60.-v Laser optical systems: design and operation
42.70.Hj Laser materials

Improvements in strain‐balanced InGaAs/GaAs optical modulators for 1047‐nm operation

D. J. Goodwill, A. C. Walker, C. R. Stanley, M. C. Holland, and M. McElhinney

Appl. Phys. Lett. 64, 1192 (1994); http://dx.doi.org/10.1063/1.110886 (3 pages) | Cited 7 times

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We demonstrate a self‐electro‐optic effect device (SEED) designed to work at 1047 nm to match the high power available from a Nd:YLF laser. The device uses a strain‐balanced InGaAs/GaAs multiple quantum well grown on a GaAs substrate with an InGaAs buffer layer of linearly graded composition. It has improved performance compared to previous devices in this system. We have obtained a single pass modulation contrast ratio of 1.74 by applying 13‐V reverse bias, and have found 99% photodetection quantum efficiency under the built‐in junction field. Bistability in a resistor‐SEED configuration is demonstrated.
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42.79.Hp Optical processors, correlators, and modulators
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
78.66.Fd III-V semiconductors

New photorefractive polymer based on multifunctional polyurethane

Y. M. Chen, Z. H. Peng, W. K. Chan, and L. P. Yu

Appl. Phys. Lett. 64, 1195 (1994); http://dx.doi.org/10.1063/1.110887 (3 pages) | Cited 12 times

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A new photorefractive polymer containing a photocarrier generator, a hole transporting compound, and a nonlinear optical chromophore covalently linked to the polymer backbone has been synthesized. Two‐beam coupling experiments have clearly demonstrated asymmetric energy exchange under zero‐field condition, a sign for photorefractivity and a maximum optical gain of 0.88 cm−1 was measured. Although it is not a net gain, the result reported here demonstrates the feasibility of rational designs of photorefractive polymers.
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42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.70.Jk Polymers and organics
78.66.Qn Polymers; organic compounds

Multi‐pulse operation of three‐wavelength pulsed Q‐switched Nd:Y3Al5O12 laser

I. Y. Milev, B. A. Ivanova, M. B. Danailov, and S. M. Saltiel

Appl. Phys. Lett. 64, 1198 (1994); http://dx.doi.org/10.1063/1.110888 (3 pages)

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By using a spatially dispersive resonator, three wavelength operation of Nd:Y3Al5O12 laser in pulsed Q‐switched regime at 1064, 1061, and 1052 nm was achieved. The laser output consisted of three pulses corresponding to the three generated wavelengths. The number of simultaneously emitted lines was increased by frequency doubling the laser output pulses in a potassium dihydrogen phosphate crystal.
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42.55.Rz Doped-insulator lasers and other solid state lasers
42.60.-v Laser optical systems: design and operation
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation

Vertical forward coupler based channel‐dropping photodetector

Hajime Sakata and Hideshi Kawasaki

Appl. Phys. Lett. 64, 1201 (1994); http://dx.doi.org/10.1063/1.110889 (3 pages) | Cited 8 times

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We demonstrated an integrated channel‐dropping photodetector in which a desired wavelength channel of the optical power is selectively coupled to a detector element. Based on a codirectionally grating‐coupled GaAs/AlGaAs filter structure, a 1.2‐nm‐wide photocurrent response was obtained in an 800‐nm‐wavelength region with a device length shorter than 1 mm. Light passing through the device exhibited an alternate notch response, promising not to terminate the unselected channels.
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42.79.Gn Optical waveguides and couplers
42.79.Sz Optical communication systems, multiplexers, and demultiplexers
85.60.Gz Photodetectors (including infrared and CCD detectors)
42.82.-m Integrated optics

Potential liquid crystal mixtures for Co2 laser application

Shin‐Tson Wu, J. D. Margerum, H. B. Meng, C. S. Hsu, and L. R. Dalton

Appl. Phys. Lett. 64, 1204 (1994); http://dx.doi.org/10.1063/1.110890 (3 pages) | Cited 8 times

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Infrared transmission of 25 liquid crystal compounds was evaluated. Based on these results, a liquid crystal mixture consisting of fluoro and dialkyl diphenyl‐diacetylene homologs was developed for CO2 laser application. This mixture exhibits a wide nematic range, high birefringence, low viscoelastic coefficient, and relatively small absorption at two CO2 laser lines: 10.59 and 10.77 μm. Its figure of merit is three times higher than the E44 commercial mixture at room temperature.
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42.70.Df Liquid crystals
42.70.Km Infrared transmitting materials
78.20.Fm Birefringence
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Photoamperic probes in scanning tunneling microscopy

M. W. J. Prins, M. C. M. M. van der Wielen, R. Jansen, D. L. Abraham, and H. van Kempen

Appl. Phys. Lett. 64, 1207 (1994); http://dx.doi.org/10.1063/1.110891 (3 pages) | Cited 20 times

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The charge generated at the apex of a semiconductor tip upon laser irradiation is utilized in a scanning tunneling microscope. We show such arrangements can produce photoinduced tunnel currents of several hundred picoamperes, sufficient for stable STM operation and sensitive enough to detect nanowatt variations in the incident optical power.
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68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy
72.40.+w Photoconduction and photovoltaic effects
73.30.+y Surface double layers, Schottky barriers, and work functions
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors

Thermal stability of titanium hydride thin films

H. Chatbi, M. Vergnat, and G. Marchal

Appl. Phys. Lett. 64, 1210 (1994); http://dx.doi.org/10.1063/1.111950 (2 pages) | Cited 14 times

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The thermal stability of titanium hydride thin films prepared by reactive evaporation is reported. The release of hydrogen is monitored by the effusion method. The gas evolution spectrum shows two peaks corresponding to the hydrogen effusion from the titanium hydride phase and to the crystallographic transformation from fcc to hcp structure, respectively.
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68.60.Dv Thermal stability; thermal effects
66.30.J- Diffusion of impurities
28.20.-v Neutron physics

Mass selection of neutral clusters in Low‐Energy Cluster Beam Deposition experiments: Is it realistic?

J. F. Roux, B. Cabaud, G. Fuchs, D. Guillot, A. Hoareau, and P. Mélinon

Appl. Phys. Lett. 64, 1212 (1994); http://dx.doi.org/10.1063/1.110892 (3 pages) | Cited 8 times

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The crucial problem in controlling and filtering the size of free neutral clusters generated by a cluster source is studied in the particular case of the Sattler source type. The present work shows that a velocity selector can be used to control the size of neutral clusters produced in the low‐energy cluster beam deposition system. This velocity selector is also used to measure the kinetic energy of free Bi clusters. The experimental results obtained for Bi clusters are compared with previous theoretical predictions.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
61.46.-w Structure of nanoscale materials

Low‐resistivity transparent In2O3 films prepared by reactive ion plating

J. I. Jeong, J. H. Moon, J. H. Hong, J. S. Kang, and Y. P. Lee

Appl. Phys. Lett. 64, 1215 (1994); http://dx.doi.org/10.1063/1.110893 (3 pages) | Cited 10 times

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Indium oxide films with an electrical resistivity of less than 1.5×10−4 Ω cm and good optical quality were prepared by the reactive ion plating of pure indium in an oxygen atmosphere of ∼10−4 Torr. The deposition rate was in the range of 500–900 Å/min, which is much higher than that of the ordinary evaporation. Hall effect measurement showed that the observed low resistivity is primarily due to the high electron mobility (≥70 cm2/V s) with carrier density up to 7×1020/cm3. These properties were correlated with the atomic concentration data by Auger electron spectroscopy and x‐ray photoelectron spectroscopy. It has been found that the films of low resistivity had the atomic ratio of O to In of 1.29–1.31.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
73.61.-r Electrical properties of specific thin films
78.66.-w Optical properties of specific thin films
42.70.-a Optical materials

On plastic flow and work hardening in strained layer heterostructures

A. Fischer and H. Richter

Appl. Phys. Lett. 64, 1218 (1994); http://dx.doi.org/10.1063/1.111957 (3 pages) | Cited 13 times

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We present an alternate model for metastable strain relaxation in heteroepitaxial semiconductor structures which includes the elastic interaction between misfit dislocations. The concept of the self‐stress of straight misfit dislocations lying in the interface in two orthogonal arrays is introduced and applied to standard expressions for the residual in‐plane epitaxial film stress of noninteracting dislocations. Our model of plastic flow and work hardening in strained layer heterostructures agrees well with the experimental work. The theoretical analysis can be applied to most of the pseudomorphic and heteroepitaxial material systems of current interest.
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68.55.-a Thin film structure and morphology
62.20.D- Elasticity
68.60.Bs Mechanical and acoustical properties
61.72.Lk Linear defects: dislocations, disclinations

Mössbauer effect measurement of the recoil‐free fraction for 57Fe implanted in a nanophase diamond film

T. W. Sinor, J. D. Standifird, F. Davanloo, K. N. Taylor, C. Hong, J. J. Carroll, and C. B. Collins

Appl. Phys. Lett. 64, 1221 (1994); http://dx.doi.org/10.1063/1.110845 (3 pages) | Cited 4 times

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The Mössbauer effect was used to investigate films of nanophase diamond (NPD) implanted with isotopically pure 57Fe at a dose of 5×1016 atoms/cm2 and an energy of 20 keV. When defects and voids created by the implantation were repaired with an overcoating layer of NPD, the recoil‐free fraction at room temperature for these samples was found to be fdia=0.94±0.06 with a corresponding Debye temperature of 1140 K. This relatively high value for f makes NPD films a promising host matrix for microgram quantities of Mössbauer isotopes.
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76.80.+y Mössbauer effect; other γ-ray spectroscopy
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
63.20.-e Phonons in crystal lattices

Autocorrelation function analysis of phase formation in the initial stage of interfacial reactions of molybdenum thin films on (111)Si

J. M. Liang and L. J. Chen

Appl. Phys. Lett. 64, 1224 (1994); http://dx.doi.org/10.1063/1.110846 (3 pages) | Cited 21 times

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Autocorrelation function (ACF) analysis has been applied to the high resolution transmission electron microscope images of amorphous interlayers formed in the interfacial reactions of ultrahigh vacuum deposited molybdenum thin films on (111)Si. Mo3Si was identified to be the first nucleated crystalline phase which is correlated to the stable structure of the amorphous Mo‐Si alloy. Both Mo3Si and Mo5Si3 were found to form simultaneously under certain annealing conditions. The results demonstrate the usefulness of the ACF analysis of atomic images in amorphous interlayers formed in the initial stage of reactions in metal thin films on silicon.
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68.55.-a Thin film structure and morphology
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.37.Lp Transmission electron microscopy (TEM)
68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics

Investigation on higher order bands in irradiated Czochralski silicon

Y. Shi, Y. D. Zheng, M. Suezawa, M. Imai, and K. Sumino

Appl. Phys. Lett. 64, 1227 (1994); http://dx.doi.org/10.1063/1.110847 (3 pages) | Cited 16 times

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Using Fourier transform infrared absorption spectroscopy and Hall‐effect measurements we have investigated the higher order bands (HOB) in the fast neutron irradiated Czochralski silicon. Introducing the thermal donors (TD) to alter the Fermi level, the defect level giving rise to the HOB is analyzed, which is proposed to be located slightly below the TD(+/++) level. Furthermore, the observation for the characteristics of the photoexcitation and decay of both the HOB and the TD+ supports the assumption that this characteristic of the HOB is associated with a slow relaxation of photoexcited carriers.
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71.55.Cn Elemental semiconductors
61.80.Hg Neutron radiation effects
78.30.-j Infrared and Raman spectra
78.40.Fy Semiconductors
72.40.+w Photoconduction and photovoltaic effects

Picosecond Raman studies of electric‐field‐induced nonequilibrium carrier distributions in GaAs‐based p‐i‐n nanostructure semiconductors

E. D. Grann, S. J. Sheih, C. Chia, K. T. Tsen, O. F. Sankey, Selim E. Guncer, D. K. Ferry, G. Maracas, Ravi Droopad, A. Salvador, A. Botcharev, and H. Morkoç

Appl. Phys. Lett. 64, 1230 (1994); http://dx.doi.org/10.1063/1.110848 (3 pages) | Cited 10 times

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Electron transport in GaAs‐based p‐i‐n nanostructure semiconductors under the application of an electric field has been studied by transient Raman spectroscopy on a picosecond time scale and at T≂80 K. For an injected carrier density of n≂2.2×1018 cm−3 and electric field intensity E=25 kV/cm, the drift velocity of electrons as high as Vd=2.5×107 cm/s was observed. These experimental results are in good agreement with Ensemble Monte Carlo calculations.
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78.47.-p Spectroscopy of solid state dynamics
78.30.Fs III-V and II-VI semiconductors
72.20.-i Conductivity phenomena in semiconductors and insulators

In situ investigation of silicon surface cleaning and damage by argon electron cyclotron resonance plasmas

Y. Z. Hu, P. P. Buaud, Y. Wang, L. Spanos, and E. A. Irene

Appl. Phys. Lett. 64, 1233 (1994); http://dx.doi.org/10.1063/1.110849 (3 pages) | Cited 4 times

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An argon electron cyclotron resonance (ECR) plasma process has been optimized to successfully remove oxide films from a silicon surface at elevated temperatures leaving smooth Si surfaces devoid of an amorphized silicon damage layer. Etch rates of over 10 nm/min have been achieved at ion energies below 100 eV. The low ion energy (−50 V dc bias) and high ion fluxes (1×1016 ions/cm2 s) represent a significant improvement from conventional Ar ion sputter cleaning processes. In situ spectroscopic ellipsometry and ex situ atomic force microscopy were used to characterize the surface condition during and after cleaning to establish a 700 °C argon plasma cleaning process for silicon. Real‐time single wavelength ellipsometry was used to study the cleaning kinetics, determine the optimal end point, and elucidate a controversy about the level of damage in the argon ECR plasma cleaning process.
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81.65.-b Surface treatments
68.35.B- Structure of clean surfaces (and surface reconstruction)
61.80.Jh Ion radiation effects

Pulsed laser deposition of epitaxial Si/TiN/Si(100) heterostructures

R. Chowdhury, X. Chen, and J. Narayan

Appl. Phys. Lett. 64, 1236 (1994); http://dx.doi.org/10.1063/1.110850 (3 pages) | Cited 17 times

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We have successfully deposited multilayer Si/TiN/Si(100) epitaxial heterostructures using pulsed laser deposition technique. This silicon‐on‐conductor device configuration has potential applications in three‐dimensional integrated circuits and radiation hardened devices. The Si and TiN films were deposited by pulsed laser (KrF: λ=248 nm, τ =25 ns) physical vapor deposition technique at a substrate temperature of 600 °C in a chamber maintained at a vacuum of ∼10−7 Torr. The epitaxial nature of the films was characterized using x‐ray diffraction, Rutherford backscattering, and high resolution transmission electron microscopy techniques. The two interfaces (100)TiN/Si(100)substrate and (100)Si/(100)TiN layers were quite sharp without any indication of interfacial reaction between them. The epitaxial relationship was found to be 〈100〉Si∥〈100〉TiN∥〈100〉Si. In the plane, four unit cells of TiN matched with three unit cells of silicon with less than 4.0% misfit. This domain matching epitaxy provides a mechanism of epitaxial growth in systems with large lattice mismatch. Modeling of the domain matching epitaxial growth in the high lattice mismatch (100)Si/(100)TiN/(100)Si system and possible device implications are discussed.
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68.55.-a Thin film structure and morphology

Stoichiometry control over a wide composition range of sputtered CuGaxIn(1−x)Se2

J. L. Hernández‐Rojas, M. L. Lucía, I. Mártil, G. González‐Díaz, J. Santamaria, and F. Sánchez‐Quesada

Appl. Phys. Lett. 64, 1239 (1994); http://dx.doi.org/10.1063/1.110851 (3 pages) | Cited 5 times

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Films of CuGaxIn(1−x)Se2 (CGIS) have been grown by rf sputtering from stoichiometric single targets with different Ga/In ratios. Adjusting growth temperature and argon pressure we are able to deposit films with a wide range of Cu contents: From CGIS Cu‐poor (16 at. %) to Cu2Se. Reevaporation of (Ga,In)2Se3 binaries is observed when substrate temperature is increased at a constant argon pressure (20 mTorr). An increase in Ar pressure from 5 to 150 mTorr at a growth temperature of 450 °C, produces a decrease in Cu atomic percentage from 24% to 16% due to a preferential diffusion of Cu sputtered atoms in the plasma. The relevant film properties of the analyzed films are found to be ruled by the Cu content. Graded composition absorbers with adequate physical properties for the fabrication of photovoltaic devices are grown with a proper choice of growth parameters.
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81.15.Cd Deposition by sputtering
68.55.Nq Composition and phase identification
72.40.+w Photoconduction and photovoltaic effects

Doping and damage dose dependence of implant induced transient enhanced diffusion below the amorphization threshold

P. B. Griffin, R. F. Lever, P. A. Packan, and J. D. Plummer

Appl. Phys. Lett. 64, 1242 (1994); http://dx.doi.org/10.1063/1.110852 (3 pages) | Cited 14 times

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Special test structures were used to isolate the dependence of transient enhanced diffusion on damage dose and on doping concentration. The structures consisted of 200 nm boron‐doped layers with an undoped silicon capping layer 300 nm thick. The boron concentrations varied from 5×1016 to 5×1018/cm3. Damage was introduced by 75 keV, Si implants with doses ranging from 1×1012 to 5×1013/cm2. Annealing at 750 °C for 120 min produced a large enhancement in the boron diffusivity. The enhancement increased with increasing Si dose, but in a sublinear manner. The enhancement decreased with increasing boron doping concentration, even for doping concentrations below the intrinsic electron concentration. A phenomenological defect‐doping reaction model is described which predicts both of these essential features of damage enhanced diffusion. We conclude that it will be necessary to treat the full coupling between defects and dopant atoms in order to model damage enhanced diffusion effects.
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61.72.uf Ge and Si
66.30.J- Diffusion of impurities
61.80.Jh Ion radiation effects

Polyaniline as a transparent electrode for polymer light‐emitting diodes: Lower operating voltage and higher efficiency

Y. Yang and A. J. Heeger

Appl. Phys. Lett. 64, 1245 (1994); http://dx.doi.org/10.1063/1.110853 (3 pages) | Cited 180 times

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We demonstrate that by using polyaniline (PANI) or a combination of (PANI) and indium/tin oxide (ITO) as the transparent anode of a polymer light‐emitting diode with poly[2‐methoxy‐5‐(2′‐ethyl‐ hexyloxy)‐1,4‐phenylene vinylene] (MEH‐PPV), as the active layer, device performance can be significantly improved. The operating voltage can be reduced by ∼30%–50% and the quantum efficiency can be increased by ∼30%–40% with respect to the devices using ITO alone as the hole‐injecting anode. The barrier height at the PANI/MEH‐PPV interface is estimated to be ∼0.08–0.12 eV, approximately half of that at the ITO/MEH‐PPV interface.
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85.60.Jb Light-emitting devices
78.60.Fi Electroluminescence
78.66.Qn Polymers; organic compounds
73.61.Ph Polymers; organic compounds

Observation of intrinsic tristability in a resonant tunneling structure

A. D. Martin, M. L. F. Lerch, P. E. Simmonds, and L. Eaves

Appl. Phys. Lett. 64, 1248 (1994); http://dx.doi.org/10.1063/1.110854 (3 pages) | Cited 47 times

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A new technique has been developed to probe the region of apparent bistability due to a tunneling resonance in the characteristic of a semiconductor asymmetric double‐barrier structure. The measuring circuit uses a voltage supply designed to have a load line with positive slope, equivalent to a voltage source and negative series resistance. The appearance of bistability and hysteresis in the characteristic is an artifact of the conventional measuring technique, which employs a load line with negative slope. The complete characteristic is found to be a continuous Z‐shaped curve between 50 and 150 K, corresponding to tristability. Equivalent circuit models for the device and voltage supply predict a narrow range of circuit parameters for which a static operating point exists inside the tristable region.
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73.40.Gk Tunneling
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
85.30.Mn Junction breakdown and tunneling devices (including resonance tunneling devices)
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