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26 May 1997

Volume 70, Issue 21, pp. 2781-2917

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The effects of high pressure on carbon nitride—in situ measurements of micro photoluminescence and infrared spectra

J. Zhao, R. Z. Che, J. R. Xu, and N. Kang

Appl. Phys. Lett. 70, 2781 (1997); http://dx.doi.org/10.1063/1.119057 (3 pages) | Cited 10 times

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The effects of high pressure up to 24 GPa on carbon nitride were studied using in situ micro photoluminescence (PL) and infrared (IR) absorption measurements at room temperature. The experiments indicate pressure-induced PL quenching with pressure increasing from 0 to 7 GPa, but the PL remains unchanged from 7 to 24 GPa. The PL results display the pressure effect of PL enhancement after release of pressure to ambient atmosphere. The IR absorption bands broaden toward low frequency after release of pressure. These may be explained by using the PL model of undistorted sp2 clusters, which, as PL centers, undergo distortion under pressure and pressure-induced local atomic rearrangement in the sample. © 1997 American Institute of Physics.
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61.50.Ks Crystallographic aspects of phase transformations; pressure effects
78.55.Hx Other solid inorganic materials
78.30.Hv Other nonmetallic inorganics

Pixelless infrared imaging utilizing a p-type quantum well infrared photodetector integrated with a light emitting diode

L. B. Allard, H. C. Liu, M. Buchanan, and Z. R. Wasilewski

Appl. Phys. Lett. 70, 2784 (1997); http://dx.doi.org/10.1063/1.119058 (3 pages) | Cited 14 times

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We present experimental results which support a recently proposed scheme for infrared imaging through the combined use of a photon frequency up-conversion device with a charge coupled device (CCD) camera. The epitaxial device consists of a long wavelength p-type GaAs/AlGaAs quantum well infrared photodetector (QWIP) on top of which is grown a shorter wavelength InGaAs/GaAs light emitting diode (LED). Upon long wavelength infrared excitation of the QWIP, near infrared light is generated by the LED whose output is directed towards a commercial CCD array where the up-converted image of the long wavelength infrared source object is formed. © 1997 American Institute of Physics.
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85.60.Gz Photodetectors (including infrared and CCD detectors)
78.66.Fd III-V semiconductors

Resonant-tunneling transmission-line relaxation oscillator

E. R. Brown, C. D. Parker, S. Verghese, M. W. Geis, and J. F. Harvey

Appl. Phys. Lett. 70, 2787 (1997); http://dx.doi.org/10.1063/1.119059 (3 pages) | Cited 15 times

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Experimental and numerical results are presented for a high-frequency oscillator consisting of a resonant-tunneling diode (RTD) series-embedded in a transmission line, one end of which is short circuited and the other end terminated with a load resistor. Like relaxation oscillators, the ac voltage across the RTD is a square wave. However, the current wave form (and hence the load wave forms) consists of a sequence of sharp pulses that are essentially locked to the fundamental mode of the transmission line. © 1997 American Institute of Physics.
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85.30.Mn Junction breakdown and tunneling devices (including resonance tunneling devices)
85.40.Ls Metallization, contacts, interconnects; device isolation

Microcavity effects in GaN epitaxial films and in Ag/GaN/sapphire structures

A. Billeb, W. Grieshaber, D. Stocker, E. F. Schubert, and R. F. Karlicek

Appl. Phys. Lett. 70, 2790 (1997); http://dx.doi.org/10.1063/1.119060 (3 pages) | Cited 49 times

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Luminescence spectra of GaN epitaxial layers grown on sapphire display a strong intensity modulation of the below-band gap transitions and on the low-energy side of the near-band gap transition. The intensity modulation is attributed to a microcavity formed by the semiconductor–air and semiconductor–substrate interface. The microcavity effect is enhanced by using metallic reflectors which increase the cavity finesse. It is shown that microcavity effects can be used to determine the refractive index of the microcavity active material. Using this method, the GaN refractive index is determined and expressed analytically by a Sellmeir fit. © 1997 American Institute of Physics.
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42.55.Sa Microcavity and microdisk lasers
78.66.Fd III-V semiconductors

A broadband antireflection coating for enhanced holographic recording and readout in bismuth silicon oxide

Z. Karim, C. Kyriakakis, and A. R. Tanguay

Appl. Phys. Lett. 70, 2793 (1997); http://dx.doi.org/10.1063/1.119061 (3 pages)

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We demonstrate a high-quality double-layer antireflection coating for high index (n = 2.61 at 514 nm) photorefractive and electro-optic bismuth silicon oxide (Bi12SiO20) crystals. The antireflection coating comprises two electron-beam-deposited quarter-wave dielectric layers of MgF2 and ZrO2, and increases the beam throughput by as much as 20% per interface at normal incidence. For holographic recording applications, the antireflection coating eliminates multiple internal reflections that produce extraneous gratings. The combination of these two factors significantly increases the diffraction efficiency and the two-beam coupling gain. Key characteristics of the double-layer coating include a broadband minimum that encompasses typical write and read wavelengths for Bi12SiO20 with normal-incidence reflectivities of less than 0.2% at 514 nm and 1% at 633 nm, respectively, and a forgiving angular dispersion for both TE and TM polarized waves with reflectivities of less than 2% for angles of incidence up to 45°. © 1997 American Institute of Physics.
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42.79.Wc Optical coatings
42.40.Eq Holographic optical elements; holographic gratings
42.70.Ln Holographic recording materials; optical storage media

Origin of direct current drift in electro-optic polymer modulator

Heuk Park, Wol-Yon Hwang, and Jang-Joo Kim

Appl. Phys. Lett. 70, 2796 (1997); http://dx.doi.org/10.1063/1.119062 (3 pages) | Cited 9 times

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Characteristics of the dc drift phenomenon in electro-optic polymer modulators have been analyzed. It is found that the dc drift originates from the difference between the dielectric relaxation times of the guiding and cladding layers. The dc drift is accelerated as the intensity of the guided light increases. Furthermore, it becomes faster when the device is exposed to visible light. The effect of the guided light and visible light on the dc drift is interpreted in terms of the photoconductivity of the guiding layer. © 1997 American Institute of Physics.
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42.79.Hp Optical processors, correlators, and modulators
42.70.Jk Polymers and organics

Infrared distributed Bragg reflectors based on amorphous SiC/SiO2 heterostructures

A. Convertino, A. Valentini, P. V. Giugno, and R. Cingolani

Appl. Phys. Lett. 70, 2799 (1997); http://dx.doi.org/10.1063/1.119063 (2 pages) | Cited 7 times

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Amorphous SiC/SiO2 distributed Bragg reflectors (DBR) deposited by ion beam sputtering at room temperature is reported on in this letter. The DBR consists of only 2.5 pairs and exhibits high peak reflectivity (84%) around ∼1.7 μm with a full width at half maximum of about 1000 nm. The measured reflectivity spectrum is well reproduced by the equivalent layer theory by using the measured refractive indices of SiC and SiO2 and including absorption losses. © 1997 American Institute of Physics.
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42.79.Fm Reflectors, beam splitters, and deflectors
78.66.Jg Amorphous semiconductors; glasses
85.50.-n Dielectric, ferroelectric, and piezoelectric devices

Composition dependence of the ultraviolet absorption edge in lithium niobate

L. Kovács, G. Ruschhaupt, K. Polgár, G. Corradi, and M. Wöhlecke

Appl. Phys. Lett. 70, 2801 (1997); http://dx.doi.org/10.1063/1.119056 (3 pages) | Cited 67 times

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A convenient and fast method to determine the composition of LiNbO3 single crystals consisting of a measurement of the position of the fundamental absorption edge in the near UV region is refined and extended to the stoichiometric range. Using unsophisticated apparatus and simple reflection correction, the proposed two-parameter calibration equation provides an absolute accuracy of 0.1 mol % with the relative accuracy reaching an unusual value of better than 0.01 mol % for near stoichiometric compositions. © 1997 American Institute of Physics.
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61.66.Bi Elemental solids
61.66.Dk Alloys
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates

Modification of the second-order optical nonlinearities in AlGaAs asymmetric multiple quantum well waveguides by quantum well intermixing

M. W. Street, N. D. Whitbread, C. J. Hamilton, B. Vögele, C. R. Stanley, D. C. Hutchings, J. H. Marsh, J. S. Aitchison, G. T. Kennedy, and W. Sibbett

Appl. Phys. Lett. 70, 2804 (1997); http://dx.doi.org/10.1063/1.119064 (3 pages) | Cited 10 times

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We demonstrate that a quantum well intermixing technique can be used to control the second-order nonlinearity χzzz(2) in an AlGaAs asymmetric coupled quantum well waveguide structure at 1.52 μm. Photoluminescence measurements also indicate that the spatial resolution of the impurity-free vacancy disordering process used for quantum well intermixing is better than 1.5 μm which should be sufficient for first-order quasiphase-matched second harmonic generation. © 1997 American Institute of Physics.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
42.65.Wi Nonlinear waveguides
78.66.Fd III-V semiconductors

Nanometer-scale Si selective epitaxial growth on Si(001) surfaces using the thermal decomposition of ultrathin oxide films

Ken Fujita, Heiji Watanabe, and Masakazu Ichikawa

Appl. Phys. Lett. 70, 2807 (1997); http://dx.doi.org/10.1063/1.119065 (3 pages) | Cited 27 times

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Nanometer-scale Si crystals were produced by selective epitaxial growth on Si(001) surfaces passivated with 0.3-nm-thick oxide films. Window areas for the growth were provided by void formation during the thermal decomposition of the oxide films. Dynamical processes of the void formation and epitaxial growth were observed at 630–730 °C by scanning tunneling microscopy. The crystal shape was a quadrangular pyramid and the typical size was 20 nm in length and 0.8 nm in height. The thin oxide films were found to act as masks for the selective epitaxial growth of nanoscale structures. © 1997 American Institute of Physics.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
81.05.Cy Elemental semiconductors
81.07.-b Nanoscale materials and structures: fabrication and characterization
81.16.-c Methods of micro- and nanofabrication and processing
85.35.-p Nanoelectronic devices

Thermodynamics of diffusion under pressure and stress: Relation to point defect mechanisms

Michael J. Aziz

Appl. Phys. Lett. 70, 2810 (1997); http://dx.doi.org/10.1063/1.119066 (3 pages) | Cited 86 times

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A thermodynamic formalism is developed for illuminating the predominant point defect mechanism of self- and impurity diffusion in silicon and is used to provide a rigorous basis for point defect-based interpretation of diffusion experiments in biaxially strained epitaxial layers in the Si–Ge system. A specific combination of the hydrostatic and biaxial stress dependences of the diffusivity is ±1 times the atomic volume, depending upon whether the predominant mechanism involves vacancies or interstitials. Experimental results for Sb diffusion in biaxially strained Si–Ge films and ab initio calculations of the activation volume for Sb diffusion by a vacancy mechanism are in quantitative agreement with no free parameters. Key parameters are identified that must be measured or calculated for a quantitative test of interstitial-based mechanisms. © 1997 American Institute of Physics.
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66.30.J- Diffusion of impurities
61.72.J- Point defects and defect clusters
81.40.Vw Pressure treatment

Relaxed Si1−xGex/Si1−x−yGexCy buffer structures with low threading dislocation density

H. J. Osten and E. Bugiel

Appl. Phys. Lett. 70, 2813 (1997); http://dx.doi.org/10.1063/1.119067 (3 pages) | Cited 26 times

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We demonstrate the growth of a relaxed, only 1 μm thick, stepwise graded buffer based on a combination of Si1−xGex and Si1−x−yGexCy. This buffer concept relies on the retardation of dislocation glide in Si1−x−yGexCy relative to strain equivalent Si1−xGex on silicon. The homogeneous Si1−xGex layer with x = 30% on top of the buffer structure is (73±5)% relaxed. For the nonoptimized buffer growth, we already find a threading dislocation density below 105 cm−2. A stepped Si1−xGex buffer with the identical thickness and strain profile grown with the same temperature ramp yields a threading dislocation density above 107 cm−2. This indicates that the addition of carbon is a promising way for new relaxed buffer concepts with low threading dislocation densities. © 1997 American Institute of Physics.
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68.55.-a Thin film structure and morphology
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Biaxially aligned buffer layers of cerium oxide, yttria stabilized zirconia, and their bilayers

S. Gnanarajan, A. Katsaros, and N. Savvides

Appl. Phys. Lett. 70, 2816 (1997); http://dx.doi.org/10.1063/1.119017 (3 pages) | Cited 16 times

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Biaxially aligned cerium oxide (CeO2) and yttria stabilized zirconia (YSZ) films were deposited on Ni-based metal (Hastelloy C276) substrates held at room temperature using ion beam assisted (IBAD) magnetron deposition with the ion beam directed at 55° to the normal of the film plane. In addition, we achieved, room-temperature epitaxial growth of CeO2 by bias sputtering to form biaxially aligned CeO2/YSZ bilayers. The crystalline structure and in-plane orientation of films was investigated by x-ray diffraction techniques. Both the IBAD CeO2 and YSZ films, and the CeO2/YSZ bilayers have a (111) pole in the ion beam direction. © 1997 American Institute of Physics.
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68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.05.Mh Cermets, ceramic and refractory composites
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.

Effects of in situ doping from B2H6 and PH3 on hydrogen desorption and the low-temperature growth mode of Si on Si(100) by remote plasma enhanced chemical vapor deposition

B. Doris, J. Fretwell, J. L. Erskine, and S. K. Banerjee

Appl. Phys. Lett. 70, 2819 (1997); http://dx.doi.org/10.1063/1.119207 (3 pages) | Cited 5 times

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We demonstrate that di- and monohydride desorption peak temperatures are shifted lower for boron-doped films and higher for phosphorus-doped films compared to intrinsic Si(100). This observation is exploited to show that the shifts in di- and monohydride desorption peak temperatures with doping are accompanied by shifts in the growth mode transition temperatures, with one exception which is discussed. This work suggests that dihydrides lead to breakdown of epitaxial growth while monohydrides promote three-dimensional epitaxial growth. © 1997 American Institute of Physics.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.05.Cy Elemental semiconductors

Luminescences from localized states in InGaN epilayers

S. Chichibu, T. Azuhata, T. Sota, and S. Nakamura

Appl. Phys. Lett. 70, 2822 (1997); http://dx.doi.org/10.1063/1.119013 (3 pages) | Cited 115 times

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Optical spectra of the bulk three-dimensional InGaN alloys were measured using the commercially available light-emitting diode devices and their wafers. The emission from undoped InxGa1−xN(x<0.1) was assigned to the recombination of excitons localized at the potential minima originating from the large compositional fluctuation. The emission from heavily impurity-doped InGaN was also pointed out related to the localized states. © 1997 American Institute of Physics.
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78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors

Observation of bistability in GaAs/AlAs superlattices

Yaohui Zhang, Robert Klann, Klaus H. Ploog, and Holger T. Grahn

Appl. Phys. Lett. 70, 2825 (1997); http://dx.doi.org/10.1063/1.119014 (3 pages) | Cited 14 times

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We have experimentally observed a new kind of current bistability in the time-averaged current-voltage (I-V) characteristic of doped, weakly coupled GaAs/AlAs superlattices, in which the transport is dominated by sequential resonant tunneling between adjacent quantum wells. Time-resolved current measurements show that in some cases the bistability is correlated with a subcritical Hopf bifurcation, while in other cases a discontinuous change of the current oscillation frequency is observed in the bistable region. The origin of this new bistability is attributed to a change of the space charge layer in the superlattice involving charging and discharging effects, which creates a feedback to the external bias. © 1997 American Institute of Physics.
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73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.50.Fq High-field and nonlinear effects
73.61.Ey III-V semiconductors

Maskless selective growth of InGaAs/InP quantum wires on (100) GaAs

J. Ahopelto, M. Sopanen, H. Lipsanen, S. Lourdudoss, E. Rodriguez Messmer, E. Höfling, J. P. Reithmaier, A. Forchel, A. Petersson, and L. Samuelson

Appl. Phys. Lett. 70, 2828 (1997); http://dx.doi.org/10.1063/1.119015 (3 pages) | Cited 6 times

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A new fabrication process to create InGaAs/InP quantum wires on (100) GaAs substrates is demonstrated. The process is based on the selectivity of the growth of InP on lines created by focused ion beam bombardment, together with the selectivity of the growth of InGaAs on the InP wires. Intense photoluminescene is observed from the wires and the emission shows clear polarization parallel and perpendicular to the wires. Cathodoluminescene images confirm that the luminescence originates from the wires. © 1997 American Institute of Physics.
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81.05.Ea III-V semiconductors
81.15.Jj Ion and electron beam-assisted deposition; ion plating
78.66.Fd III-V semiconductors
78.60.Fi Electroluminescence

Thermodynamic considerations in epitaxial growth of GaAs1−xNx solid solutions

Y. Qiu, S. A. Nikishin, H. Temkin, V. A. Elyukhin, and Yu. A. Kudriavtsev

Appl. Phys. Lett. 70, 2831 (1997); http://dx.doi.org/10.1063/1.119016 (3 pages) | Cited 33 times

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We describe epitaxial growth of solid solutions of GaAs1−xNx with high nitrogen concentrations. The equilibrium constants of reactions needed for the formation of single phase alloys are calculated and compared with experimental pressure and growth temperature data. We show good agreement between the experiment and the calculated thermodynamic growth conditions. In addition, our calculations indicate that at room temperature the alloys of GaAs1−xNx are either unstable or metastable with respect to decomposition, for the entire range of compositions. © 1997 American Institute of Physics.
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81.10.Aj Theory and models of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation
81.05.Ea III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Thermoelectric transport in quantum well superlattices

D. A. Broido and T. L. Reinecke

Appl. Phys. Lett. 70, 2834 (1997); http://dx.doi.org/10.1063/1.119018 (3 pages) | Cited 34 times

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A full theory of thermoelectric transport in superlattices, including the well width and energy dependence of the optical and acoustic phonon scattering and the effects of confinement in raising valley degeneracy is developed. It is shown that these features result in qualitatively significant modifications in the predicted figure of merit of superlattice systems. Results are given for PbTe superlattices, and comments are made on recent experimental results for such systems. © 1997 American Institute of Physics.
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73.50.Lw Thermoelectric effects
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Photoluminescence study of Si1−xGex/Si surface quantum wells

Y. Kishimoto, Y. Shiraki, and S. Fukatsu

Appl. Phys. Lett. 70, 2837 (1997); http://dx.doi.org/10.1063/1.119019 (3 pages) | Cited 6 times

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We report a photoluminescence (PL) study of Si1−xGex/Si surface quantum wells (SFQWs). The PL peak energies are found to be affected by strain relaxation in Ge-rich SFQWs while a PL energy lowering was observed for x ⩽ 0.47 as compared to buried quantum wells capped with Si. Exciton localization in the lateral direction is suggested to be the dominant PL mechanism in SFQWs rather than perpendicular confinement effects that are expected for SFQWs. PL degradation and a spectral dominance switch over to newly developing lower energy peaks were clearly observed after prolonged air exposure. © 1997 American Institute of Physics.
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78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors

The formation of nanostructures on silicon surfaces in the presence of hydrogen

O. Teschke, D. M. Soares, and L. A. O. Nunes

Appl. Phys. Lett. 70, 2840 (1997); http://dx.doi.org/10.1063/1.119055 (3 pages) | Cited 3 times

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The presence of hydrogen in HF solutions at a silicon substrate surface is shown to be sufficient to produce a photoluminescent porous silicon layer. The photoluminescence measurements of bubbled and anodized samples show similar spectra when illuminated with UV radiation. This is strong evidence that the hydrogen produced by the anodic silicon dissolution reaction is also responsible for the formation of nanostructures. © 1997 American Institute of Physics.
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81.65.Cf Surface cleaning, etching, patterning
78.66.Db Elemental semiconductors and insulators
78.55.Mb Porous materials

In situ monitoring of molecular beam epitaxy using specularly scattered ion beam current oscillations

J. G. C. Labanda and S. A. Barnett

Appl. Phys. Lett. 70, 2843 (1997); http://dx.doi.org/10.1063/1.119020 (3 pages) | Cited 11 times

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Specular scattering of 3 keV He ions was observed for incidence angles of 2°–6° from GaAs(001). During molecular beam epitaxy, the scattered ion current dropped rapidly upon opening the Ga shutter, showed damped oscillations, and then increased gradually upon closing the shutter. The oscillation periods corresponded to monolayer growth times. Oscillation amplitudes decreased with increasing substrate temperature, indicating a transition to step-flow growth. The oscillations were not a diffraction effect, allowing a quantitative interpretation based on scattering by adatoms and step edges. © 1997 American Institute of Physics.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
61.05.Np Atom, molecule, and ion scattering (for structure determination only)

Be–Zn interdiffusion and its influence on InGaAsP lasers fabricated by hybrid growth of chemical beam epitaxy and metalorganic vapor phase epitaxy

Hideo Sugiura, Susum Kondo, Manabu Mitsuhara, Shinichi Matsumoto, and Masayuki Itoh

Appl. Phys. Lett. 70, 2846 (1997); http://dx.doi.org/10.1063/1.119053 (3 pages) | Cited 1 time

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We have studied the dopant redistribution between a chemical beam epitaxy (CBE) grown InGaAsP laser structure and a metalorganic vapor phase epitaxy overgrown InP layer. Secondary ion mass spectroscopy analysis reveals that Zn and Be atoms deeply interdiffuse in the adjacent InP layers for a Zn doping of 1018 cm−3 and that a fraction of Zn atoms go through the CBE InP and penetrate the laser structure guide layer. We have found that the Zn outdiffusion is significantly suppressed by reducing the Be doping concentration from 1018 to 5×1017 cm−3. As a result, for tensile-strained InGaAsP multiquantum well (MQW) buried-heterostructure (BH) lasers, the threshold current and internal loss decrease from 13 to 9 mA and 15 to 10 cm−1 by lowering the Be doping, respectively. InAsP MQW BH lasers have an internal loss of 5.5 cm−1. © 1997 American Institute of Physics.
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42.55.Px Semiconductor lasers; laser diodes
66.30.Ny Chemical interdiffusion; diffusion barriers
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.15.Kk Vapor phase epitaxy; growth from vapor phase

Comparison of high field electron transport in GaN and GaAs

B. E. Foutz, L. F. Eastman, U. V. Bhapkar, and M. S. Shur

Appl. Phys. Lett. 70, 2849 (1997); http://dx.doi.org/10.1063/1.119021 (3 pages) | Cited 75 times

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An ensemble Monte Carlo simulation is used to compare high field electron transport in bulk GaN and GaAs. In particular, velocity overshoot and electron transit times are examined. In GaN, we find the steady state velocity of the electrons is the most important factor determining transit time over distances longer than 0.2 μm. Over shorter distances velocity overshoot effects in GaN at high fields are comparable to those in GaAs. We estimate the minimum transit time across a 1 μm GaN sample to be about 3.0 ps. Similar calculations for GaAs yield 5.4 ps. © 1997 American Institute of Physics.
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72.20.Ht High-field and nonlinear effects
72.80.Ey III-V and II-VI semiconductors

Noise-free avalanche multiplication in Si solid state photomultipliers

Jungsang Kim, Yoshihisa Yamamoto, and Henry H. Hogue

Appl. Phys. Lett. 70, 2852 (1997); http://dx.doi.org/10.1063/1.119022 (3 pages) | Cited 21 times

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Si solid state photomultipliers utilize impact ionization of shallow impurity donor levels to create an avalanche multiplication when triggered by a photoexcited hole. The distribution of pulse height from a single photon detection event shows narrow dispersion, which implies that the avalanche multiplication process in these devices is inherently noise-free. We have measured the excess noise factor using two different techniques, digital pulse height analysis and analog noise power measurement. The results demonstrate nearly noise-free avalanche multiplication accomplished in these devices. © 1997 American Institute of Physics.
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85.60.Ha Photomultipliers; phototubes and photocathodes
72.20.Ht High-field and nonlinear effects
72.70.+m Noise processes and phenomena
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