EP1492908A2 - Influence de la geometrie des surfaces sur des proprietes metalliques - Google Patents

Influence de la geometrie des surfaces sur des proprietes metalliques

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Publication number
EP1492908A2
EP1492908A2 EP03714343A EP03714343A EP1492908A2 EP 1492908 A2 EP1492908 A2 EP 1492908A2 EP 03714343 A EP03714343 A EP 03714343A EP 03714343 A EP03714343 A EP 03714343A EP 1492908 A2 EP1492908 A2 EP 1492908A2
Authority
EP
European Patent Office
Prior art keywords
layer
depth
metal
indents
electrode pair
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03714343A
Other languages
German (de)
English (en)
Other versions
EP1492908A4 (fr
Inventor
Avto Tavkhelidze
Stuart Harbron
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Borealis Technical Ltd
Original Assignee
Borealis Technical Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US10/234,498 external-priority patent/US7140102B2/en
Application filed by Borealis Technical Ltd filed Critical Borealis Technical Ltd
Publication of EP1492908A2 publication Critical patent/EP1492908A2/fr
Publication of EP1492908A4 publication Critical patent/EP1492908A4/fr
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/30—Cold cathodes, e.g. field-emissive cathode
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/60—Forming conductive regions or layers, e.g. electrodes

Definitions

  • the present invention is concerned with methods for increasing the Fermi level of a metal and for promoting the transfer of elementary particles across a potential energy barrier.
  • the present invention also relates to making a surface having a geometric pattern for nanoelectronics applications, and more particularly, to making a surface having a geometric pattern that creates a wave interference pattern that facilitates the emission of electrons from the surface.
  • Geometric patterns are used in a variety of applications. Generally, a laser, chemical, or other means etches geometric patterns on a surface of solid materials, such as silicon, metal, and the like, for example, as described in U.S. Patent No. 5,888,846. Geometric patterns may be used for creating optical disk storage systems, semi-conductor chips, and photo mask manufacturing, as described in U.S. Patent No. 5,503,963. Surfaces capable of enhancing the passage of electrons through a potential energy barrier on the border between a solid body and a vacuum, such as those described in U.S. Patent Nos . 6,281,514 and 6,117,344, should have patterns of the dimensions of 5-10 nm.
  • a disadvantage of e-beam or ion beam milling is that the distribution of intensity inside the beam is not uniform, which means that structures produced using these methods do not have a uniform shape. In particular, the edges of the milled areas are always rounded, repeating the shape of intensity distribution inside the beam. Such rounding is more or less acceptable depending on the type of device fabricated. However, for devices working on the basis of wave interference this type of rounding is less acceptable, because wave interference depends greatly both on the dimensions and the shape of the structure .
  • the present invention is concerned with methods for increasing the Fermi level of a metal.
  • a wall of a potential energy box is modified, which changes the boundary conditions for the wave function of an elementary particle inside the potential energy box. New boundary conditions decrease the number of solutions of Schroedinger' s equation.
  • a method for increasing the Fermi energy in a metal comprises creating an indented or protruded structure on the surface of a metal .
  • the depth of the indents or height of protrusions is equal to a, and the thickness of the metal is te + a.
  • the minimum value for a is chosen to be greater than the surface roughness of the metal.
  • the value of a is chosen to be equal to or less than x/5.
  • the width of the indentations or protrusions is chosen to be at least 2 times the value of a.
  • a method for making a surface having a geometric pattern that promotes the emission and transmission of electrons across a surface potential energy barrier includes depositing a metal layer on a substrate.
  • the method also includes exposing specific areas of the metal layer to an electromagnetic energy source and to remove the metal layer in a geometric pattern.
  • the method also includes etching the exposed geometric pattern to form indents in the surface, using a liquid etchant or plasma.
  • the method also includes removing the remaining metal layer from the surface.
  • the method also includes creating De Broglie wave interference with the geometric pattern in the surface.
  • the method also includes removing the metal layer from the surface.
  • a technical advantage of the present invention is that the method yields a geometric pattern having sharply-defined edges.
  • a further technical advantage of the present invention is that it promotes the transfer of electrons across a potential barrier, and for a particular energy barrier that exists on the border between a solid body and a vacuum, provides a surface with a sharply defined geometric pattern that causes destructive interference between reflected electron probability waves (De Broglie waves) .
  • Another technical advantage of the present invention is that it allows for an increase in particle emission through a potential energy barrier.
  • a surface has a sharply defined geometric pattern of a dimension that promotes destructive interference of the reflected elementary particle probability waves.
  • Figure 1 is a diagrammatic representation of a three-dimensional potential energy box. Potential energy is zero everywhere inside the box volume and is infinity everywhere outside of box volume.
  • Figure 2 is a diagrammatic representation of a three-dimensional potential energy box with indented wall, a is the depth of the indent and b is width of the indent. Potential energy is zero everywhere inside the box volume and is infinity everywhere outside of box volume. Maximum dimension in X direction is L x +a.
  • Figure 4 is a diagrammatic representation of a possible realization of metal with indented wall. Indents are etched on the surface of thin metal film deposited on insulating substrate.
  • Figure 6 is a diagrammatic representation of a possible realization of metal with indented wall. Indents are etched on the surface of an insulating substrate, on which is deposited a thin metal film.
  • Figure 7 depicts a surface and a layer in accordance with an embodiment of the present invention.
  • Figure 8 depicts an exposure of a layer to an energy source in accordance with an embodiment of the present invention.
  • Figure 9 depicts a geometric pattern and a layer on a surface in accordance with an embodiment of the present invention.
  • Figure 10 depicts etching a surface in accordance with an embodiment of the present invention.
  • Figure 11 depicts an etched geometric pattern in a surface in accordance with an embodiment of the present invention.
  • Figure 12 depicts a wave interference barrier in a surface in accordance with an embodiment of the present invention.
  • Figure 13 depicts a process for making paired electrodes.
  • Figure 14 depicts a process for making paired electrodes.
  • Figure 15 depicts a process for making a diode device.
  • FIG. 2 shows a modified potential energy box (MPEB) 10
  • five walls of the potential energy box are plane and the sixth wall 12 is indented.
  • the indents on the sixth wall 12 have the shape of strips having depth of a and width of b.
  • the length of the box in the X direction Lx + a, in the Y direction is Ly and in the Z direction is Lz .
  • the potential energy of a particle inside the box volume is equal to zero, and outside the box volume is equal to U. There is a potential energy jump from zero to U at any point on the walls of the box.
  • Volume in k space for three-dimensional case changes like linear dimension on k line in the one- dimensional case. Because of that results can be easily extrapolate from the one-dimensional case to the three-dimensional case. The importance of this is illustrated by the following thought experiment in which there are two potential energy boxes of the same dimensions, one an OPEB with all walls plane, and another a MPEB with one wall modified.
  • the n th fermion will have (L x +a) /a times more wave vector in the MPEB than in the OPEB.
  • the energy of the n th fermion in the MPEB will be [(L x +a)/a] 2 times higher than in the OPEB. This is only true for the one-dimensional case.
  • the ratio of energies of the n th pair of fermions will be
  • E m /E [(L x +a)/a] 2 3 (11)
  • E m is the energy of n th fermion in the MPEB and E is the energy of the n th fermion in the OPEB.
  • Index n is skipped in formula (11) because the ratio of energies does not depend on it.
  • Free electrons inside the solid state is one of the examples of fermions inside the potential energy box.
  • the theory of electron gas inside the lattice is well developed and is based on different models, the most simple of which is the quantum model of free electrons, which gives excellent results when applied to most metals. It is well known that free electrons in metal form a Fermi gas.
  • n 0, ⁇ 1, ⁇ 2, ⁇ 3, ...
  • Cyclic boundary conditions leave the density of quantum states unchanged, and at the same time they allow the study running waves instead of standing waves, which is useful for physical interpretation.
  • the distance between quantum states in k space in k x direction will become 2 ⁇ /a instead of 2 ⁇ / (L x +a) .
  • the number of quantum states per unit volume in k space will decrease (L x +a) /a times.
  • Metal retains its electrical neutrality, which means that the same number of free electrons have to occupy separate quantum states inside the metal. Because the number of quantum states per unit volume in k space is less than in the case of ordinary metal, some electrons will have to occupy quantum states with k>k F . This shows that the Fermi wave vector and the corresponding Fermi energy level will increase.
  • the volume of metal box shown in Figure 2 is
  • the volume of elementary cell in k space is
  • the Fermi energy in the metal with the modified wall will relate to the Fermi energy in the same metal with the plane wall as follows:
  • a thin metal film 40 is deposited on the insulator substrate 42, and indents 44 are etched into the film. Indents have depth a and width b . Most metals oxidize under the influence of atmosphere. Even when placed in vacuum metals oxidize with time because of influence of residual gases. Typical oxides have depth of 50-100 A, which is considerable on the scale discussed.
  • film 40 comprises an oxidation-resistant metal.
  • film 40 comprises gold.
  • film 40 is deposited so that it is homogenous and not granular: if the metallic film is granular, the wave function will have an interruption on the border of two grains, and the indented wall's influence on the boundary conditions will be compromised because the wave function will not be continuous on the whole length of L x +a.
  • film 40 is a monocrystal . It is necessary to note here that lattice impurities do not influence free electrons with energies E ⁇ E F . In order to interact with an impurity inside the lattice, the electron should exchange the energy with the impurity in the lattice. That type of energy exchange is forbidden because all quantum states nearby are already occupied. The mean free path of an electron, sitting deep in Fermi sea is formally infinite. So the material of the film can have impurities, but it should not be granular. That type of requirement is quite easy to satisfy for thin metal films.
  • film 40 is plane.
  • the surface of the film should be as plane as possible, as surface roughness leads to the scattering of de Broglie waves. Scattering is considerable for the wavelengths of the order or less than the roughness of the surface.
  • Substrates with a roughness of 5 A are commercially available.
  • Metal film deposited on such substrate can also have a surface with the same roughness.
  • the de Broglie wavelength of a free electron in metal sitting on the Fermi level is approximately 10 A.
  • FIG. 5 shows a comparison of Fermi and vacuum levels of some single valence metals on the energy scale and simultaneously on the scale of de Broglie wavelength of the electron calculated from formula (3) . It is evident that 5 A roughness of the surface is enough to eliminate energy barrier (in the case L x ⁇ pa) for such metals as Cs and Na. The same roughness creates gap from zero to approximately Fermi level in energy spectrum of such metals as Au and Ag.
  • Values for a and b are chosen to reduce diffraction of the standing wave (see formulas (2) and (4) that show that plane waves are solutions of the Schroedinger equation) .
  • a standing wave comprises two plane waves moving in -lithe direction of X and -X. Wave diffraction will take place on the indent. Diffraction on the indents will lead to the wave "ignoring" the indent, which changes all calculations above.
  • values for a and b are chosen so that the diffraction of the wave on the indent is negligible, or
  • the thickness of film 40 is chosen so' that equation (7) is valid.
  • L x is a multiple of a. If equation (7) is not valid, then the number of quantum states will be less than the number given by formula (8) . Decreasing the number of quantum states will magnify the effect of increasing of E F , but it will be problematic to control work function decrease without keeping (7) valid during the metal film deposition stage, as well as during indent etching.
  • L x is chosen so that it is not a multiple of a.
  • depth of the indent should be much more than the surface roughness. Consequently, the minimum possible a is 30-50A.
  • the indents have a depth of a depth approximately 5 to 20 times the surface roughness.
  • the minimum possible b will be 300- 50 ⁇ A.
  • the width is approximately 5 to 15 times the depth.
  • the thickness of the metal film should be at least 180-300A, and is preferably 150 to 75 ⁇ A.
  • films of such thickness still repeat the substrate surface shape, and the film surface roughness does not exceed the roughness of the base substrate.
  • the same is not true for metal films with a thickness of 1000 A and more, because a thick film surface does not follow the surface of the substrate. That puts another limit 15>(L x /a)>5 on the dimensions of the structure, when metal films are deposited on the substrates.
  • a thin metal film 60 is deposited on a structured insulator substrate 62.
  • the structured substrate as indentations of depth a and the distance between the indents is b. This means that the metal film has thickness L x and has indents of depth a and width b, but now the active surface is plane.
  • FIG. 7 depicts a surface 102 of a material 103 and a metal layer 104 in accordance with one embodiment of the present invention.
  • Material 103 may be comprised of a variety of substances, and may be metallic or a semiconductor.
  • material 103 is resistant to etching in any direction except the direction perpendicular to the surface 102.
  • surface 102 is able to emit electrons via thermionic, secondary, photoelectric and/or field emission.
  • surface 102 is comprised of • silicon.
  • Layer 104 comprises a material that is different to material 103, and is relatively more sensitive to e-beam or ion beam or more readily ablated than material 103. Preferably, layer 104 does not promote a chemical reaction with surface but is adsorbed to the surface. In a preferred embodiment, layer 104 comprises soft metals such as lead, tin or gold. Layer 104 is deposited on surface 102 such that layer 104 is in adhesive contact with surface 102. Layer 104 covers surface 102 in a uniform manner such that surface 102 is protected from the environment. Preferably layer 104 is a thin film having a depth of 20 to 200 Angstroms. Preferably surface " 102 is substantially flat, but layer 104 may be also deposited after milling on surface 102.
  • e-beam 304 operates at a low intensity and cuts the ablatable material of layer 104.
  • Ion beam or beam of other particles could be used instead of e-beam.
  • the source positions the beam at the center of a hole 308 within layer 104. Hole 308 represents that part of layer 104 that has been removed by the beam. Because no beam is focused ideally layer 104 is being removed more in the center and less on the periphery of the beam.
  • the beam repeats the process of cutting holes into layer 104 shown in Figure 2, to create the geometric shape in the material 103 as shown.
  • the geometric shape includes strips 402, which are the remaining material of layer 104. These preferably comprise lead, tin, or gold. Most preferably, strips 402 comprise gold.
  • Geometric shape 420 has edges enclosed by strips 402.
  • the beam can produce other geometric shapes in the layer 104, such as squares, rectangles, a single strip, or a stepped shape.
  • etchant 510 reacts with surface 102, but not with strips 402 nor with the portion of the surface 102 that is covered with strips 402.
  • the etchant etches surface 102 in a precise and uniform manner.
  • the etchant may be a chemical that reacts with surface 102, or it may be a plasma.
  • etchant 510 is a liquid.
  • indents 606 are created by the reaction of etchant 510 with surface 102 as described above to yield surface 602 having the geometric pattern etched into its surface.
  • the depths a of indents 606 are controlled by the application of etchant 510.
  • Strips 402 reside on top of the non-indented regions within geometric pattern surface 602.
  • the indents created by etchant 510 correlate with geometric shapes 420 cut by beam 304 as described above.
  • strips 402 are removed from geometric pattern surface 602 to expose non-indented regions 710. Strips 402 may be removed by vacuum evaporation or other removal techniques that do not damage the underlying surface.
  • Protrusions 710 are the raised surfaces of geometric pattern surface 602.
  • geometric pattern surface 602 has a distinct geometric pattern formed by indents 606 and protrusions710.
  • Geometric pattern surface 602 includes spaced indents 606 and protrusions 710. The depth of the indents and the width of the protrusions are about equal across geometric pattern surface 602. The magnitude of defined depth a of indent 606 and it's associated width b are discussed above.
  • step 1300 a layer of titanium 1304 is deposited on a wafer 1302.
  • the wafer may comprise silicon or molybdenum.
  • step 1310 a layer of silver 1312 is deposited on the layer of titanium.
  • step 1320 involves the formation of an indented surface in the silver layer, which may be achieved as described above, particularly as shown in Figures 7 to 12.
  • step 1330 a layer of copper 1332 is grown electrochemically on the layer of silver to form composite 1334, which is an electrode pair precursor.
  • step 1340 composite 1334 is heated, which causes it to open as shown, forming a pair of matching electrodes, 1342 and 1344.
  • step 1400 An alternative approach for forming matched electrodes, one of which has the properties associated with an indented structure, is shown in Figure 14.
  • an indented surface is formed on the wafer 1402.
  • the indented surface may be formed as described above, particularly as shown in Figures 7 to 12.
  • step 1410 a layer of silver is deposited on the indented wafer 1402, and in a further step 1420, a layer of titanium 1422 is deposited on the silver layer.
  • step 1430 a layer of copper 1432 is grown electrochemically on the layer of silver to form composite 1434, which is an electrode pair precursor.
  • composite 1434 formed is heated, which causes it to open as shown, forming a pair of matching electrodes, 1442 and 1444.
  • the electrode pairs made in steps 1340 and 1440 may be utilized to make diode devices, and a preferred process is depicted in Figure 15, where in step 1500 a first substrate 1502 is brought into contact with a polished end of a quartz tube 90.
  • Substrate 1502 is any material which may be bonded to quartz, and which has a similar thermal expansion coefficient to quartz.
  • Preferably substrate 1502 is molybdenum, or silicon doped to. render at least a portion of it electrically conductive.
  • Substrate 1502 has a depression 1504 across part of its surface.
  • Substrate 1502 also has a locating hole 1506 in its surface.
  • liquid metal 1512 is introduced into depression 1502.
  • the liquid metal is a metal having a high temperature of vaporization, and which is liquid under the conditions of operation of the device.
  • the high temperature of vaporization ensures that the vapor from the liquid does not degrade the vacuum within the finished device.
  • the liquid metal is a mixture of Indium and Gallium.
  • Composite 78 is positioned so that alignment pin 1514 is positioned above locating hole 1506.
  • Composite 78 is composite 1334 depicted in Figure 13, or is composite 1434 depicted in Figure 14; for simplicity, the indented interface is not shown.
  • Alignment pin 1514 which is pre-machined, is placed on the composite near the end of the electrolytic growth phase; this results in its attachment to the layer of copper 1332 or 1432.
  • the diameter of the alignment pin is the same as the diameter of the locating hole.
  • step 1520 the polished silicon periphery of the composite 78 is contacted with the other polished end of the quartz tube 90; at the same time, the attachment pin seats in locating hole.
  • substrate 1502 is heated so that locating hole expands; when the assemblage is subsequently cooled, there is a tight fit between the alignment pin and the locating hole. High pressure is applied to this assemblage, which accelerates the chemical reaction between the polished silicon periphery of the composites and the polished ends of the quartz tube, bonding the polished surfaces to form the assemblage depicted in step 1520.
  • step 1530 the assemblage is heated, and a signal applied to the quartz tube to cause the composite to open as shown, forming two electrodes, 72 and 74.
  • the adhesion of the silver and titanium is controlled so that when the electrode composite/quartz tube shown in Figure 15 is heated, the electrode composite opens as shown, forming a pair of matching electrodes, 72 and 74.
  • the tight fit between the alignment pin and the locating hole ensures that the electrodes 72 and 74 do not slide relative to one another.
  • the quartz tube has pairs of electrodes disposed on its inner and outer surfaces (not shown) for controlling the dimensions of the tubular element.
  • the crystal orientation of the tube is preferably substantially constant, and may be aligned either parallel to, or perpendicular to the axis of the tube.
  • An electric field may be applied to the tube, which causes it to expand or contract longitudinally.
  • An advantage of such a tubular actuator is that it serves both as actuator and as housing simultaneously. Housing provides mechanical strength together with vacuum sealing. External mechanical shock/vibrations heat the external housing first, and are compensated immediately by actuator. It has been shown that modifying the wall of a potential energy box changes the boundary conditions for the wave function of an elementary particle inside the potential energy box. New boundary conditions decrease the number of solutions to Schroedinger' s equation for a particle inside the MPEB.
  • the decrease in the number of quantum states results in an increase in the energy of the n th particle situated in the potential energy box.
  • General results obtained for fermions in the potential energy box were extrapolated to the particular case of free electrons inside the metal. Calculations were made within the limit of quantum theory of free electrons . It was shown that in the case of a certain geometry of the metal wall, the Fermi level inside the metal will increase. A controllable increase in the Fermi level, and the corresponding decrease of the work function of the metal will have practical use for devices working on the basis of electron motion, electron emission, electron tunneling etc.
  • the method for enhancing passage of elementary particles through a potential barrier has many applications; for example, the method may be applied to thermionic converters, vacuum diode heat pumps and photoelectric converters, where a reduction in work function gives real benefits in terms of efficiency or operating characteristics.
  • the elementary particle emitting surface has many further applications.
  • the surface is useful on emitter electrodes and other cathodes because it promotes the emission of electrons. It is also useful on collector electrodes and other anodes because it promotes the passage of electrons into the electrode.
  • the surface also has utility in the field of cold cathodes generally, and electrodes incorporating such a surface can be used.
  • indents of a required depth and pitch have been described which run across the surface of the slab in a trench-like fashion.
  • Other geometries having indents of the required depth and pitch also fall within the intended scope of the invention.
  • these could be checkerboard shape, with the black squares for example, representing surface indentations, and white squares, protrusions.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Cold Cathode And The Manufacture (AREA)

Abstract

L'influence de la géométrie des surfaces sur des propriétés métalliques est étudiée dans le cadre de la théorie quantique des électrons libres. Il a été prouvé qu'une surface métallique peut être modifiée avec des stries à motifs afin d'améliorer le niveau de Fermi dans le métal, ce qui entraîne une diminution de la fonction de travail des électrons. Cet effet pourrait exister dans n'importe quel système quantique contenant des fermions dans un boîtier d'énergie potentielle. L'invention concerne aussi un procédé de fabrication de surfaces à nanostructures présentant des caractéristiques perpendiculaires avec des rebords tranchants.
EP03714343A 2002-03-22 2003-03-24 Influence de la geometrie des surfaces sur des proprietes metalliques Withdrawn EP1492908A4 (fr)

Applications Claiming Priority (9)

Application Number Priority Date Filing Date Title
US36656302P 2002-03-22 2002-03-22
US36656402P 2002-03-22 2002-03-22
US366563P 2002-03-22
US366564P 2002-03-22
US37350802P 2002-04-17 2002-04-17
US373508P 2002-04-17
US10/234,498 US7140102B2 (en) 2001-09-02 2002-09-03 Electrode sandwich separation
US234498 2002-09-03
PCT/US2003/008907 WO2003083177A2 (fr) 2002-03-22 2003-03-24 Influence de la geometrie des surfaces sur des proprietes metalliques

Publications (2)

Publication Number Publication Date
EP1492908A2 true EP1492908A2 (fr) 2005-01-05
EP1492908A4 EP1492908A4 (fr) 2006-08-23

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EP (1) EP1492908A4 (fr)
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WO (1) WO2003083177A2 (fr)

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US6680214B1 (en) 1998-06-08 2004-01-20 Borealis Technical Limited Artificial band gap
US8574663B2 (en) 2002-03-22 2013-11-05 Borealis Technical Limited Surface pairs
US7305839B2 (en) 2004-06-30 2007-12-11 General Electric Company Thermal transfer device and system and method incorporating same
US7260939B2 (en) 2004-12-17 2007-08-28 General Electric Company Thermal transfer device and system and method incorporating same
GB0501413D0 (en) 2005-01-24 2005-03-02 Tavkhelidze Avto Method for modification of built in potential of diodes
US8541678B2 (en) * 2005-03-14 2013-09-24 Borealis Technical Limited Thermionic/thermotunneling thermo-electrical converter
US7589348B2 (en) 2005-03-14 2009-09-15 Borealis Technical Limited Thermal tunneling gap diode with integrated spacers and vacuum seal
US7498507B2 (en) 2005-03-16 2009-03-03 General Electric Company Device for solid state thermal transfer and power generation
US7427786B1 (en) 2006-01-24 2008-09-23 Borealis Technical Limited Diode device utilizing bellows
US8713195B2 (en) 2006-02-10 2014-04-29 Cisco Technology, Inc. Method and system for streaming digital video content to a client in a digital video network
US8227885B2 (en) 2006-07-05 2012-07-24 Borealis Technical Limited Selective light absorbing semiconductor surface
GB0617934D0 (en) 2006-09-12 2006-10-18 Borealis Tech Ltd Transistor
GB0618268D0 (en) 2006-09-18 2006-10-25 Tavkhelidze Avto High efficiency solar cell with selective light absorbing surface
GB2466937B (en) 2007-09-24 2012-07-04 Borealis Tech Ltd Composite structure gap-diode thermopower generator or heat pump
US7928630B2 (en) 2007-09-24 2011-04-19 Borealis Technical Limited Monolithic thermionic converter
GB2583565B (en) 2019-02-14 2023-05-03 Borealis Tech Ltd Low work function materials

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US5068535A (en) * 1988-03-07 1991-11-26 University Of Houston - University Park Time-of-flight ion-scattering spectrometer for scattering and recoiling for electron density and structure
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US6117344A (en) * 1998-03-20 2000-09-12 Borealis Technical Limited Method for manufacturing low work function surfaces

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AU2003218346A8 (en) 2003-10-13
AU2003218346A1 (en) 2003-10-13
WO2003083177A3 (fr) 2004-03-04
WO2003083177A2 (fr) 2003-10-09
EP1492908A4 (fr) 2006-08-23

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