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21 Mar 1994

Volume 64, Issue 12, pp. 1463-1593

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Low threshold, wafer fused long wavelength vertical cavity lasers

J. J. Dudley, D. I. Babić, R. Mirin, L. Yang, B. I. Miller, R. J. Ram, T. Reynolds, E. L. Hu, and J. E. Bowers

Appl. Phys. Lett. 64, 1463 (1994); http://dx.doi.org/10.1063/1.111913 (3 pages) | Cited 67 times

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We demonstrate electrically injected InGaAsP (1.3 μm) vertical cavity lasers (VCLs) fabricated on GaAs substrates and employing GaAs/AlAs mirrors. The technique of wafer fusion allows for integration of GaAs/AlAs mirrors with InP double heterostructures without degradation of device performance, despite a 3.7% lattice mismatch between the wafers. The wafer fused VCLs have the lowest threshold current (9 mA) and lowest threshold current density (9.5 kA/cm2) and the highest characteristic temperature (T0=67 K) reported to date of any room‐temperature long wavelength VCL.
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42.55.Px Semiconductor lasers; laser diodes
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions

Integration of GaAs vertical‐cavity surface emitting laser on Si by substrate removal

Hsi‐Jen J. Yeh and John S. Smith

Appl. Phys. Lett. 64, 1466 (1994); http://dx.doi.org/10.1063/1.111887 (3 pages) | Cited 18 times

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Substrate removal techniques are attractive for the integration of III‐V compound semiconductor devices on Si for the integration of optical and electronic devices, and on thermally conducting substrates for heat sinking. Here we discuss the bonding of strained quantum well InGaAs vertical‐cavity surface‐emitting lasers on both Si and Cu substrates. The GaAs substrates are then removed by selective etching. Lasing was achieved with pulsed electrical pumping with Jth=2.5 kA/cm2. The performance characteristics of the Si and Cu bonded devices are compared.  
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42.82.Cr Fabrication techniques; lithography, pattern transfer
78.66.Fd III-V semiconductors

Quantum confinement and strain effects on the lateral mode stability of an unstable resonator semiconductor laser

P. Ru, W. W. Chow, J. V. Moloney, and S. W. Koch

Appl. Phys. Lett. 64, 1469 (1994); http://dx.doi.org/10.1063/1.111888 (3 pages) | Cited 3 times

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The gain medium effects on the lateral mode stability of an unstable resonator semiconductor laser are investigated. A physical optics laser model based on a many‐body semiclassical laser theory of the gain medium is used. The consistent treatment of bulk, quantum well, and strained quantum well structures shows that quantum confinement or strain can result in single lateral mode operation over significantly wider ranges of unstable resonator configurations and gain medium excitation.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Steady‐state performance of microcavity surface‐emitting lasers with quantum confinement of electrons and photons

Igor Vurgaftman and Jasprit Singh

Appl. Phys. Lett. 64, 1472 (1994); http://dx.doi.org/10.1063/1.111889 (3 pages) | Cited 3 times

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In conventional surface‐emitting lasers, the photon density of states is essentially that of a bulk material and, therefore, spontaneous emission rates are the same as in bulk. However, in an ideal laser, one would like to have a single photon mode coincident with the peak in the material gain so that zero‐threshold lasing occurs. This possibility is examined for a surface‐emitting microcavity laser. The photon density of states for realistic GaAs‐based microcavity structures (4 μm length and 0.5–4 μm lateral width) is derived from solutions to the wave equation in the cavity. This density of states is used to study the properties of microcavity lasers with compressively strained quantum well active media by using the exact form of spontaneous emission rate in the rate equations. It is found that when the lateral dimension approaches 0.5 μm, all optical power is present in a single resonant photon mode (the lasing mode), although additional leaky and propagating modes exist. The spontaneous emission factors and threshold current densities are derived for a few microcavity lasers. It is found that for microcavities with lateral dimensions and aspect ratios practical in experimental realization, the ideal ‘‘thresholdless’’ behavior is not observed, although the threshold current density is reduced to ≊60 A/cm2 compared with 160 A/cm2 calculated for lasers with cross sections typical for conventional surface‐emitting lasers.
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42.55.Px Semiconductor lasers; laser diodes

Optimum strain for the suppression of Auger recombination effects in compressively strained InGaAs/InGaAsP quantum well lasers

Wayne W. Lui, Takayuki Yamanaka, Yuzo Yoshikuni, Shunji Seki, and Kiyoyuki Yokoyama

Appl. Phys. Lett. 64, 1475 (1994); http://dx.doi.org/10.1063/1.111890 (3 pages) | Cited 2 times

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The primary mechanism that leads to the suppression of Auger recombination effects in compressively strained quantum wells is found due to the existence and the appropriate positioning of negative‐curvature zones in the first valence subbands (zones in k space where the radial curvature of the first valence subband is negative). By studying previous Monte Carlo calculation results, strong correlations between the negative‐curvature zones and its adverse effects on Auger recombinations are observed, thereby confirming this finding. Through this understanding, it is inferred that compressive strain is most effective for reduction of Auger recombination effects when the amount of strain is no more than 1.0%. Beyond 1.0%, the gain in device performance with respect to more compressive strain is expected to be greatly diminished.
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72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
42.55.Px Semiconductor lasers; laser diodes

High power coherent two‐dimensional semiconductor laser array

Steve Sanders, Robert Waarts, Derek Nam, David Welch, Don Scifres, John C. Ehlert, Wiliam J. Cassarly, J. Michael Finlan, and Kevin M. Flood

Appl. Phys. Lett. 64, 1478 (1994); http://dx.doi.org/10.1063/1.111992 (3 pages) | Cited 7 times

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Diffraction limited 1.4 W pulsed output power is demonstrated from a two‐dimensional 144 element surface emitting laser array placed in an external Talbot cavity. Phase locking of the array is achieved with a parallel phase sensing and control system based on phase contrast imaging used in combination with a liquid crystal array in the laser cavity. Diffraction limited cw operation is also demonstrated.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.60.Fc Modulation, tuning, and mode locking

Structural origin of the 5.16 eV optical absorption band in silica and Ge‐doped silica

T. E. Tsai, E. J. Friebele, M. Rajaram, and S. Mukhapadhyay

Appl. Phys. Lett. 64, 1481 (1994); http://dx.doi.org/10.1063/1.111891 (3 pages) | Cited 19 times

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The origin of the 5.16 eV absorption band observed in silica and Ge‐doped silica was studied using optical and electron spin resonance (ESR) measurements. The band was observed only in samples containing Ge, suggesting that it is related to the Ge impurity in silica, while a lack of correlation between the ESR intensity of the induced hydrogen‐associated doublet and the absorption coefficient of the 5.16 eV band indicates that it is not related to two‐coordinated Si or Ge. The observation of the absorption coefficient increased as the square root of the Ge concentration demonstrates that the 5.16 eV band is not related to two‐coordinated Ge defects but that it is an oxygen deficiency center of the divacancy type associated with Ge.
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42.70.Ce Glasses, quartz
61.43.Fs Glasses
78.30.-j Infrared and Raman spectra
78.40.Fy Semiconductors

Large‐numerical‐aperture microlens fabrication by one‐step etching and mass‐transport smoothing

Z. L. Liau, D. E. Mull, C. L. Dennis, R. C. Williamson, and R. G. Waarts

Appl. Phys. Lett. 64, 1484 (1994); http://dx.doi.org/10.1063/1.111892 (3 pages) | Cited 20 times

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Precision f/1 microlenses have been fabricated in GaP by smoothing a multiple‐mesa structure etched with a designed width and length variation. High‐resolution lithography and ion‐beam‐ assisted etching were used for mesa definition and resulted in accurate lens profiles after mass‐transport smoothing at 900–1070 °C. This much simplified fabrication technique is highly promising for efficient, diffraction‐limited micro‐optical elements.
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42.79.Bh Lenses, prisms and mirrors
81.65.-b Surface treatments
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces

Room temperature spectral hole burning and elimination of photodarkening in sol‐gel derived CdS quantum dots

K. Kang, A. D. Kepner, Y. Z. Hu, S. W. Koch, N. Peyghambarian, C.‐Y. Li, T. Takada, Y. Kao, and J. D. Mackenzie

Appl. Phys. Lett. 64, 1487 (1994); http://dx.doi.org/10.1063/1.111867 (3 pages) | Cited 32 times

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Spectral hole burning at room temperature is used as a technique to compare optical nonlinearities of semiconductor quantum dot materials prepared by the sol‐gel and glass fusion techniques. In an effort to understand the mechanism of photodarkening in quantum dots and assess its effect on optical nonlinearities, we prepared and characterized three representative samples with similar dot sizes. We found that photodarkening can be reduced substantially by controlling the media surrounding the dots. The sol‐gel derived samples with 80 wt % SiO2 do not exhibit appreciable photodarkening while the melt‐quenched glasses with 56 wt % SiO2 exhibit strong photodarkening effects at room temperature which results in reduction of their optical nonlinearity by a factor of ≂20 compared with the sol‐gel derived samples.
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73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.66.Hf II-VI semiconductors

Continuous‐wave, dual‐cavity, doubly resonant, optical parametric oscillator

F. G. Colville, M. J. Padgett, and M. H. Dunn

Appl. Phys. Lett. 64, 1490 (1994); http://dx.doi.org/10.1063/1.111868 (3 pages) | Cited 20 times

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We have demonstrated a continuous‐wave optical parametric oscillator that uses separate optical cavities to resonate independently the nondegenerate signal and idler frequencies. The three‐mirror cavity utilizes the type II phase‐matching geometry in lithium triborate, with the orthogonally polarized signal and idler fields separated by an intracavity, dichroic‐coated, Brewster‐angled beam splitter. This dual‐cavity oscillator can overcome mode and cluster hopping effects, which are characteristic of doubly resonant, continuous‐wave optical parametric oscillators. We measure a pump power threshold of ≊200 mW and smooth tuning over ≊0.4 GHz. The tuning range is limited by pump resonance effects within the idler cavity.
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.79.Nv Optical frequency converters

Acoustic microscopy by atomic force microscopy

U. Rabe and W. Arnold

Appl. Phys. Lett. 64, 1493 (1994); http://dx.doi.org/10.1063/1.111869 (3 pages) | Cited 99 times

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We have constructed an atomic force microscope enabling one to image the topography of a sample, and to monitor simultaneously ultrasonic surface vibrations in the MHz range. For detection of the distribution of the ultrasonic vibration amplitude, a part of the position‐sensing light beam reflected from the cantilever is directed to an external knife‐edge detector. Acoustic images taken on the surface of a wafer show a lateral resolution of about 100 nm at an ultrasonic frequency of 20 MHz.
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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
43.35.Sx Acoustooptical effects, optoacoustics, acoustical visualization, acoustical microscopy, and acoustical holography

Energy transfer from radio frequency sheath accelerated CF+3 and Ar+ ions to a Si wafer

H. Kersten, R. J. M. M. Snijkers, J. Schulze, G. M. W. Kroesen, H. Deutsch, and F. J. de Hoog

Appl. Phys. Lett. 64, 1496 (1994); http://dx.doi.org/10.1063/1.111870 (3 pages) | Cited 6 times

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The thermal energy flux which a rf plasma delivers to a silicon surface has been studied by a calorimetric method. The energy flux appears to be proportional to the product of the average ion energy and the ion flux, which was calculated from the Bohm criterion using measured plasma parameters. Furthermore, the value and energy dependence of the kinetic energy transfer efficiency (about 0.5) suggests that the microscopic interaction of impinging ions in the eV range with a silicon surface can be described by a binary collision model.
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52.40.Hf Plasma-material interactions; boundary layer effects
52.80.Pi High-frequency and RF discharges

Microstructure and epitaxy of c‐axis oriented single crystal cobalt films grown on rigid underlayers

Kannan M. Krishnan, Y. Honda, Y. Hirayama, and M. Futamoto

Appl. Phys. Lett. 64, 1499 (1994); http://dx.doi.org/10.1063/1.111871 (3 pages) | Cited 7 times

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We have established the conditions to grow c‐axis oriented Co films on mica substrates and characterized their crystallography and microstructure in detail. In particular, these films are single crystal, c‐axis oriented, Cohcp and are grown epitaxially by e‐beam evaporation on either Ti or Ru underlayers. The orientation relationship is basically (00.1)mica∥(00.1)underlayer∥(00.1)Co, and [11.0]mica∥[10.0]underlayer∥[10.0]Co. Films grown on Ru underlayers have an average grain size of 50–80 nm with negligible fcc content. For Ti underlayers, the 15–20 nm size grains contain a small fraction of fcc cobalt. The growth of such films makes it possible to measure fundamental magnetic properties of the individual microstructural components/grains of a thin film recording media.
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68.55.-a Thin film structure and morphology
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Fullerenes as precursors for diamond film growth without hydrogen or oxygen additions

Dieter M. Gruen, Shengzhong Liu, Alan R. Krauss, Jianshu Luo, and Xianzheng Pan

Appl. Phys. Lett. 64, 1502 (1994); http://dx.doi.org/10.1063/1.111872 (3 pages) | Cited 75 times

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Diamond films are predominantly grown using approximately 1% of a hydrocarbon precursor in hydrogen gas. Hydrogen is generally believed to be necessary for the diamond thin‐film growth process. However, hydrogen in varying amounts is inevitably incorporated in the growing diamond lattice, leading to structural defects. We report here the successful growth of diamond films using fullerene precursors in an argon microwave plasma, a unique development achieved without the addition of hydrogen or oxygen. We speculate that collisional fragmentation of C60 to give C2 could be responsible for the high growth rate of the very‐fine‐grained diamond films.
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68.55.Nq Composition and phase identification
68.55.-a Thin film structure and morphology

Degradation mechanisms and improvement of thermal stability of CoSi2/polycrystalline Si layers

Wei‐Ming Chen, Sanjay K. Banerjee, and Jack C. Lee

Appl. Phys. Lett. 64, 1505 (1994); http://dx.doi.org/10.1063/1.111873 (3 pages) | Cited 15 times

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Degradation mechanisms of CoSi2/polycrystalline Si (polycide) films have been investigated. CoSi2 was formed on various silicon substrates (stacked or one‐layer structures composed of polycrystalline Si 800–10 800 Å and amorphous Si 800–3000 Å). The thermal stability of these silicide films were examined using four‐point probe measurement. It was found that the microstructure of the underlying silicon substrate, rather than the grain size of the CoSi2 or the silicide/polycrystalline Si interface, has the greatest influence on the thermal stability of the polycide films. The CoSi2 formed on as‐deposited amorphous Si provides the maximum thermal stability. Those films are stable at 1000 °C up to 120 s, even for undoped polycide films.
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68.60.Dv Thermal stability; thermal effects
81.65.-b Surface treatments

Thermal stability of Ti/Pt/Au nonalloyed ohmic contacts on InN

F. Ren, C. R. Abernathy, S. J. Pearton, and P. W. Wisk

Appl. Phys. Lett. 64, 1508 (1994); http://dx.doi.org/10.1063/1.111874 (3 pages) | Cited 25 times

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Extremely low contact resistance of nonalloyed Ti/Pt/Au metallization on n‐type InN is demonstrated. The contacts were annealed at different temperatures up to 420 °C to investigate their thermal stability. A low contact resistivity of 1.8×10−7 Ω cm2 was measured at room temperature using the transmission line method. This was due to the extremely high doping level (5×1020 cm−3) in the InN. After 300 °C annealing, the contact resistivity increased to 2.4×10−7 Ω cm2. For 360 °C annealing, the contact morphology showed some degradation, but the contact resistivity was almost the same as at 300 °C. There was serious degradation of the contacts after 420 °C annealing. The morphology became very rough, and the contact and sheet resistances increased by factors of 3–5 times. This degradation is believed due to the decomposition of the InN film. The contact resistivities between n‐type epitaxial GaAs and InN were also investigated, and showed values around 10−4 Ω cm2.
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73.40.Cg Contact resistance, contact potential
73.61.-r Electrical properties of specific thin films

Diffusion barrier effects of transition metals for Cu/M/Si multilayers (M=Cr, Ti, Nb, Mo, Ta, W)

H. Ono, T. Nakano, and T. Ohta

Appl. Phys. Lett. 64, 1511 (1994); http://dx.doi.org/10.1063/1.111875 (3 pages) | Cited 77 times

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In order to find appropriate diffusion barrier materials for Cu, the diffusion of Cu into Si through various barrier metals M (M=Cr, Ti, Nb, Mo, Ta, W) was investigated. The behavior of Cu in Cu/M/Si multilayers was measured after annealing using x‐ray diffraction analysis, secondary ion mass spectroscopy, Rutherford backscattering spectroscopy, and electric resistance change. Only Cu/Ta/Si and Cu/W/Si multilayers retained their multilayer structures after annealing at 600 °C×1 h in H2 without resistivity increases. Multilayers of the other metals did not retain their structures after the same annealing condition. This difference in the barrier properties of the transition metals appeared to be related to the metal‐Cu binary phase diagrams and their self‐diffusion coefficients.
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68.35.Fx Diffusion; interface formation
73.61.At Metal and metallic alloys

Growth of cubic boron nitride on Si(100) by neutralized nitrogen ion bombardment

Ming Lu, A. Bousetta, R. Sukach, A. Bensaoula, K. Walters, K. Eipers‐Smith, and A. Schultz

Appl. Phys. Lett. 64, 1514 (1994); http://dx.doi.org/10.1063/1.111876 (3 pages) | Cited 30 times

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Highly cubic phase and stoichiometric boron nitride films were deposited on Si(100) substrates using a neutralized nitrogen beam and electron beam evaporation of boron. High intensity, focused, and low‐energy neutralized nitrogen beam was supplied using a newly developed neutralizer atomic beam ion source (NABS) adapted to a Kaufman‐type ion source. The films were grown at substrate temperatures in the range 400–500 °C and a boron evaporation rate of 0.2 A/s. Infrared transmittance spectra of the films showed that a highly cubic phase (80%) was obtained in the area of the focused beam. These films were compared to those obtained using similar conditions but with the NABS disconnected from the ion source, and it was found that the cubic phase content decreases drastically (10%). The results show that the NABS was the determining factor in enhancing the formation of the cubic boron nitride films. Furthermore, the addition of Ar to N, which is reported to increase the momentum transfer and promote the formation of the cubic phase, did not play a significant role when the NABS was used.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.55.Nq Composition and phase identification
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)

Experimental study of p layers in ‘‘tunnel’’ junctions for high efficiency amorphous silicon alloy multijunction solar cells and modules

A. Banerjee, J. Yang, T. Glatfelter, K. Hoffman, and S. Guha

Appl. Phys. Lett. 64, 1517 (1994); http://dx.doi.org/10.1063/1.111877 (3 pages) | Cited 16 times

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The role of the p layer in the formation of good quality ‘‘tunnel’’ junctions and its dependence on the attainment of high efficiency hydrogenated amorphous silicon alloy (a‐Si:H) multijunction cells has been investigated. A new technique, namely, the evaluation of the current‐voltage characteristics of the NIPN structure consisting of a single‐junction n‐i‐p cell with an overlying doped n layer, has been developed for the determination of losses at the ‘‘tunnel’’ junction. Using an optimized p layer, an initial conversion efficiency of 11.4% has been obtained on a double junction a‐Si:H module of aperture area ∼900 cm2.
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84.60.Jt Photoelectric conversion
73.61.Jc Amorphous semiconductors; glasses
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
72.80.Ng Disordered solids

Vibrational mode for nitrogen in zinc selenide

H. J. Stein

Appl. Phys. Lett. 64, 1520 (1994); http://dx.doi.org/10.1063/1.111878 (3 pages) | Cited 12 times

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The first observation of a localized vibrational mode for N in ZnSe by infrared absorption is reported. Nitrogen was introduced into internal reflection plates of polycrystalline ZnSe by ion implantation. Isotopic substitution confirmed assignment of the absorption to N, and the band frequency is consistent with N on Se sites. Coimplantation with deuterium decreased the N band intensity and introduced a band for Zn—D. These deuterium effects which increase upon annealing between 200 and 300 °C are ascribed to a breaking of Zn—N bonds to form Zn—D bonds and a relaxation of N toward threefold coordination.
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61.72.Cc Kinetics of defect formation and annealing
61.72.uj III-V and II-VI semiconductors
78.30.Fs III-V and II-VI semiconductors

Monolayer thickness control of InxGa1−xAs/GaAs quantum wells grown by metalorganic molecular beam epitaxy

B. Courboulès, J. Massies, C. Deparis, N. Grandjean, J. Leymarie, C. Monier, A. M. Vasson, and A. Vasson

Appl. Phys. Lett. 64, 1523 (1994); http://dx.doi.org/10.1063/1.111879 (3 pages) | Cited 4 times

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High strained InxGa1−xAs/GaAs quantum well (QW) structures have been grown by metalorganic molecular beam epitaxy (MOMBE) with the aim of investigating the capability of this epitaxial growth method in terms of thickness control. Emission lines from QWs with thicknesses differing by 1 monolayer (ML) are well resolved by low temperature photoluminescence. It is thus demonstrated that MOMBE allows a thickness control with 1 ML precision.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
78.66.Fd III-V semiconductors
61.05.jh Low-energy electron diffraction (LEED) and reflection high-energy electron diffraction (RHEED)

Optical characterization of submonolayer and monolayer InAs structures grown in a GaAs matrix on (100) and high‐index surfaces

P. D. Wang, N. N. Ledentsov, C. M. Sotomayor Torres, P. S. Kop’ev, and V. M. Ustinov

Appl. Phys. Lett. 64, 1526 (1994); http://dx.doi.org/10.1063/1.111880 (3 pages) | Cited 81 times

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We studied the optical properties of InAs/GaAs heterostructures with InAs average layer thickness ranging from 1 Å [one‐third of a monolayer (ML)] to 4 ML grown on (100) and (311) surfaces. Extremely high optical quality was revealed for the structures with ultrasmall InAs coverage. We attribute the improvements to the first stage of InAs growth on the GaAs surface which we refer to as submonolayer epitaxy. Optical anisotropy found in photoluminescence (PL), as well as in PL excitation spectra indicates a highly anisotropic growth mode for InAs molecules on the GaAs (100) surface. An InAs/GaAs superlattice composed of submonolayer InAs exhibits greatly improved luminescence efficiency at room temperature and much better nonequilibrium carrier capture compared to either the (In,Ga)As alloy or an InAs/GaAs superlattice composed of monolayer‐thick InAs layers with the same average In composition.
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78.66.Fd III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Conduction‐band states of thin InAs/AlSb quantum wells

Timothy B. Boykin

Appl. Phys. Lett. 64, 1529 (1994); http://dx.doi.org/10.1063/1.111881 (3 pages) | Cited 3 times

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We study the conduction‐band states of thin InAs quantum wells confined by relatively thick AlSb barriers with a ten‐band tight‐binding model, considering the results in the context of recent experiments. For the 1 monolayer well structure, we find that the wave function has significant evanescent‐state contributions both in the well and barriers, while we find that the wave function of the 5 monolayer device is mostly Γ‐like throughout.
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73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions

Uniaxial stress dependence of exciton emission from seeded physical vapor transport ZnSe

H. L. Cotal, J. B. Maxson, S. W. S. McKeever, and E. Cantwell

Appl. Phys. Lett. 64, 1532 (1994); http://dx.doi.org/10.1063/1.111882 (3 pages) | Cited 3 times

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Uniaxial stress dependence of photoluminescence has been employed to study the exciton emission in seeded physical vapor transport ZnSe. By examining the stress behavior of the photoluminescence line Ix , it is suggested that this line is due to recombination of a deep donor‐bound exciton. From measurements of the π‐ and σ‐polarized luminescence spectra the heavy‐hole and light‐hole components of the exciton emissions were followed as a function of applied stress. From these data the linear hydrostatic and shear deformation potential constants were calculated to be a=−5.1 and b=−0.74 eV, respectively.
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71.35.-y Excitons and related phenomena
71.55.Gs II-VI semiconductors
71.70.Ej Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect
78.55.Et II-VI semiconductors

Optical gain of optically pumped Al0.1Ga0.9N/GaN double heterostructure at room temperature

S. T. Kim, H. Amano, I. Akasaki, and N. Koide

Appl. Phys. Lett. 64, 1535 (1994); http://dx.doi.org/10.1063/1.111883 (2 pages) | Cited 30 times

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In this letter, we report the measurement of the gain of an optically pumped Al0.1Ga0.9N/GaN double heterostructure (DH) which was prepared on a sapphire substrate by metalorganic vapor phase epitaxy using an AlN buffer layer. At room temperature, the optical gain of stimulated emission from Al0.1Ga0.9N/GaN DH was measured to be 160 cm−1 at pumping power density of 200 kW/cm2.
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78.45.+h Stimulated emission
78.66.Fd III-V semiconductors
85.60.-q Optoelectronic devices
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