EP1756335A4 - Nanoparticule de germanium et d'alliage de germanium et procede de realisation associe - Google Patents

Nanoparticule de germanium et d'alliage de germanium et procede de realisation associe

Info

Publication number
EP1756335A4
EP1756335A4 EP05785299A EP05785299A EP1756335A4 EP 1756335 A4 EP1756335 A4 EP 1756335A4 EP 05785299 A EP05785299 A EP 05785299A EP 05785299 A EP05785299 A EP 05785299A EP 1756335 A4 EP1756335 A4 EP 1756335A4
Authority
EP
European Patent Office
Prior art keywords
germanium
etchant solution
nanoparticles
germanium alloy
alloy electrode
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Withdrawn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
EP05785299A
Other languages
German (de)
English (en)
Other versions
EP1756335A2 (fr
Inventor
Munir H Nayfeh
Laila Abuhassan
Ammar M Nayfeh
Yia-Chung Chang
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.)
University of Illinois at Urbana Champaign
University of Illinois System
Original Assignee
University of Illinois at Urbana Champaign
University of Illinois System
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 US10/849,536 external-priority patent/US20050072679A1/en
Application filed by University of Illinois at Urbana Champaign, University of Illinois System filed Critical University of Illinois at Urbana Champaign
Publication of EP1756335A2 publication Critical patent/EP1756335A2/fr
Publication of EP1756335A4 publication Critical patent/EP1756335A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C5/00—Electrolytic production, recovery or refining of metal powders or porous metal masses
    • C25C5/02—Electrolytic production, recovery or refining of metal powders or porous metal masses from solutions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/02—Silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B41/00—Obtaining germanium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H01S3/163—Solid materials characterised by a crystal matrix
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
    • H01S5/041—Optical pumping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/3027—IV compounds
    • H01S5/3031—Si

Definitions

  • a field of the invention is nanomaterials.
  • BACKGROUND ART Silicon nanoparticles of ⁇ 1 nm diameter have shown stimulated emissions.
  • Bulk silicon is an optically dull indirect bandgap material, having a 1.1 eV indirect bandgap, and a 3.2 eV direct bandgap.
  • a lnm silicon nanoparticle effectively creates a new wideband direct gap material, with an energy gap of 3.55 eV, and highly efficient optical activity.
  • a lnm silicon nanoparticle indirect band gap of 1.1 eV corresponds to a wavelength of 1.1 ⁇ m, which is in the infrared region.
  • Our previous work with lnm silicon nanoparticles has shown moderate emission activity in the infrared region.
  • the uniformly dimensioned lnm silicon nanoparticles (having about 1 part in one thousand or less of greater dimensions) produced in earlier work have characteristic blue emissions. See, e.g., Akcakir et al, "Detection of luminescent single ultrasmall silicon nanoparticles using fluctuation correlation spectroscopy", Appl. Phys. Lett. 76 (14), p. 1857 (April 3, 2000). Silicon nanoparticles have also been synthesized with H- or O- termination, or functionalized with N- , or C-linkages. Previous work also produced a family of uniformly dimensioned nanoparticles with distinct particle sizes in the 1-3 nm range, which fluoresce spectacularly, and an additional particle that emits in the infrared band.
  • Optical interconnects have many uses. An example use is for highspeed data communications between servers, either at the cabinet-to-cabinet or board-to-board levels. Another use is for chip-level interconnects.
  • III-V systems such as GaAs or InP-InGaGa PiN.
  • Group IV materials hold special interest due to their benign nature and because of fabrication advantages.
  • Silicon based detectors for example, may be fabricated in a conventional silicon CMOS process, which typically can be implemented at lower cost than the Group III-V fabrication processes.
  • Conventional optical detectors made on compound semiconductor substrates are bonded with a bulk silicon die for a multi-chip solution that is relatively costly.
  • bulk silicon-based photodetectors have limited detection efficiency and wavelength range.
  • Germanium or gallium arsenide -based systems offer better absorption and sensitivity at 1300 and 1550 nm over bulk silicon.
  • Nanoparticle-based photodetectors also referred to as quantum dot photodetectors, present an opportunity for enhancing the photon-to-current conversion efficiency compared to bulk devices to a degree that can alleviate or eliminate the need for amplification circuitry used in conventional systems to make use of the small photocurrent created in conventional bulk silicon detector devices.
  • Systems based on films of Si, Ge, and GeSi nanoparticles or quantum dots have been recently demonstrated, but with moderate efficiency.
  • Ge-based photodetector utilizing films consisting of large quantum substructures (50 nm) have respective responses of 130, 0.16, and 0.08 mA/W under the wavelengths of 820, 1300, and 1550 nm.
  • These levels of current response are below those that would provide a simple integration into optoelectronic devices for short reach optoelectronic communications. Higher performance, particularly at 820 nm, would make it feasible to integrate optoelectronic devices into silicon chips for short-reach optical communications.
  • an electrochemical etching of crystalline germanium or a germanium alloy produces well-segregated chromatic clusters of nanoparticles. Distinct strong bands appear in the photoluminescence spectra under 350 nm excitation with the lowest peaks in wavelength identified to be at
  • the material may be dispersed into a discrete set of luminescent nanoparticles of 1 -3 nm in diameter, which may be prepared into colloids and reconstituted into films, crystals, etc.
  • FIGs. 1A and IB show the photoluminescence spectra of the etched Ge wafer taken from different regions of an experimental sample under 365 nm excitation;
  • FIG. 2 shows the photoluminescence of an experimental GE sample in the infrared taken under an excitation source of 365 nm;
  • FIG. 3 shows the FTIR spectrum of an experimental Ge sample.
  • the invention concerns germanium and germanium alloy nanoparticles and methods for making the same. Infrared emissions from nanaparticles command a special interest in myriad applications. Highly-efficient nanomaterial-based photodetectors or phototransistors in the infrared can form the basis for chip-to-chip and board-to-board optical interconnects. In relation to bulk silicon, bulk germanium reduces the indirect band gap (0.66 vs. 1.1 eV), and the direct band gaps (0.9 vs. 3.2 eV), and one use of germanium nanoparticles of the invention is to extend the photosensitive response into the infrared.
  • etching processes of crystalline germanium or a germanium alloy in a chemical etchant solution e.g., HF/H 2 O /H 2 O
  • a chemical etchant solution e.g., HF/H 2 O /H 2 O
  • Sensitive Si/Ge nanoparticle material-based devices can therefore cover a wide range of wavelengths from near UV to infrared.
  • a particularly useful application of efficient response in the infrared band is use in infrared biological imaging applications.
  • a method for creating clusters of the nanoparticles of an embodiment of the invention is a bipolar electrochemical treatment which involves insertion of bulk germanium or germanium alloy, e.g. a wafer, into a chemical etch solution, in the presence of an external current.
  • the germanium serves as an electrode in an electrochemical etching process.
  • Another electrode also contacts the chemical etch bath.
  • current is reversed.
  • a gradual advance of the wafer into the bath may be used to increase the area of etching.
  • An example rate is about one millimeter per minute. Current is reversed, in this case, as a gradual retreat of the wafer is conducted.
  • current reversal may be executed after a lift of the wafer to its original height to begin a second period of gradual advance of the wafer.
  • a different etchant solution i.e., an aqueous HCl/methanol electrolyte bath is used. The etching process creates a layer of uniformly dimensioned Ge nanoparticles on the surface of the bulk germanium. After etching, the Ge electrode with Ge nanoparticles formed on its surface is separated from the etchant solution.
  • the Ge with the nanoparticle surface may then be rinsed to remove any etchant solution.
  • the particles may be removed from the bulk material by an agitation process, e.g, shaking, banging, scraping or ultrasonic agitation, the latter of which is preferred.
  • an agitation process e.g, shaking, banging, scraping or ultrasonic agitation, the latter of which is preferred.
  • any method which separates the nanoparticles from the etched bulk Ge or Ge alloy surface is suitable, but a solvent with breaking force supplied by ultrasound waves is preferred.
  • Example solvents include acetone, alcohol, water, and other organic solvents.
  • H-terminated germanium particles may be functionalized with alkynes. For example, refluxing in a 20% 1-dodecene solution in mesitylene (v/v) for several hours results in the incorporation of surface-bound dodecyl moieties. It is a thermally induced hydrogermylation reaction.
  • the bulk germanium is replaced with an alloy of silicon-germanium. Electrochemical etching as discussed above is applied to disperse the alloy into nanoparticles.
  • Alloys may be produced by ion implantation or molecular beam epitaxy procedures.
  • An example embodiment uses Germanium-silicon wafers of 20-80 (Ge-silicon) composition. For this ratio, a nanoparticle of 1 nm in diameter may have Si 24 Ge 5 configuration (24 silicon atoms and 5 Ge atoms), or we can use 80-20 (Ge-silicon) composition which gives Ge 24 Si 5 (5 silicon atoms and 24 Ge atoms).
  • the proportion of Ge to the alloy element permits tuning the composition, which allows tuning of the wavelength response of alloyed or doped nanoparticles. Our theoretical simulations show that several high quality Si/Ge nanoparticles configurations are possible. We have conducted experiments to demonstrate the method of the invention.
  • the wafer was etched for 5 minutes at anodizing current of 180 mA, providing a density of 350 mA/cm.2.
  • the polarity of the electrodes was reversed to perform a cathodization etch step for 2 minutes.
  • well-segregated chromatic clusters were produced, which under 365 nm UV excitation, exhibit ultrabright blue, green, and yellow/orange photoluminescence, as well as very efficient infrared radiation.
  • Both HF and H 2 O are reactive with Ge oxide, thus the incorporation of the highly oxidative peroxide enhances the etching rate, producing much smaller nanostructures.
  • the sharp rise on the blue edge of the band is caused by the cutoff filter.
  • the emission band peaks at 490 nm. In many cases there is a hint of a yellow shoulder at 580 nm.
  • a fiber optic spectrometer which includes optical fibers to transport the excitation and to extract the emission.
  • a holographic grating that is a polymer replica of a master grating. It is a near infrared grating with groove density of 600/mm with a blaze angle of 1 ⁇ m and with best efficiency in the range 0.65-1.1 ⁇ m.
  • FIG. 2 shows the spectrum in the infrared, taken with an excitation source of 365 nm. There is a photoluminescence band in the infrared part of the spectrum (680-1100 nm). The line shape of the infrared band is asymmetric rising sharply at 680 nm and dropping slowly well into the infrared at ⁇ 1100 nm.
  • a method for producing a discrete family of silicon nanoparticles includes particles of diameters 1, 1.67, 2.15, 2.85, and 3.7 nm. See, e.g., Belomoin et al. "Observation of a magic discrete family of ultrabright Si nanoparticles," Appl. Phys. Lett. 80(5), p 841 (February 4, 2002); and United States Published Patent Application 20020070121 to Nayfeh et al. Based upon the size difference between Si and Ge, Ge nanoparticles would have corresponding sizes of 1, 1.75, 2.25, 3.0, and 3.9 nm. Significant differences between Si and Ge exist in the infrared part of the spectrum.
  • Silicon nanoparticles of different sizes give band edge luminescence at 1160-1300 nm with an efficiency of 6 % of the visible emission.
  • Germanium nanoparticles give photoluminescence in the range 680- 1100 nm with an efficiency that is comparable or larger than the visible emission. Germanium is also expected to produce luminescence in the range 1,500 to 3,000 nm.
  • the extension of strong emission into the infrared in Ge is due to the reduced bandgaps in bulk Ge compared to Si (0.66 vs. 1.1 eV indirect), and (0.9 vs. 3.2 eV direct).
  • the method of the invention produces Ge and Ge-alloy nanoparticles having a size in the range of ⁇ l-3nm
  • a Teflon chamber cylinder is sealed on the bottom by the wafer.
  • a metal plate makes electrical contact with the backside of the wafer.
  • the cylinder is filled with the etching solution.
  • the etchant is a 1 : 1 mixture of HC1, and methanol.
  • a platinum wire electrode is immersed in the etchant normal to the substrate at a certain height (2 cm for example) above it.
  • the wafer With the germanium substrate acting as the anode, and the platinum wire acting as a cathode, the wafer is anodized for 5 minutes at an appropriate anodizing current density for etching, e.g., ⁇ 230 mA/cm
  • an appropriate anodizing current density for etching e.g., ⁇ 230 mA/cm
  • the polarity of the electrodes is reversed to perform a cathodization step for 2 minutes.
  • the etchant is then removed, and the wafer is rinsed with water followed by an acetone rinse and a drying period. Similar spectra of particle clusters are observed, but the distribution is now skewed towards the orange/red sizes.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Organic Chemistry (AREA)
  • Nanotechnology (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Materials Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Composite Materials (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Electrochemistry (AREA)
  • Metallurgy (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Weting (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
  • Electrolytic Production Of Metals (AREA)

Abstract

L'invention concerne une gravure électrochimique de germanium cristallin ou d'un alliage de germanium qui produit des agrégats chromatiques bien séparés de nanoparticules. De fortes zones distinctes apparaissent dans les spectres de photoluminescence sous une excitation de 350 nm avec les crêtes les plus faibles dans la longueur d'ondes identifiée comme étant à 430, 480, 580 et 680-1100 nm. La matière peut être répartie en un jeu discret de nanoparticules luminescentes de 1 à 3 nm de diamètre, lesquelles peuvent être préparées en colloïdes et reconstituées en films, cristaux, etc.
EP05785299A 2004-05-19 2005-05-16 Nanoparticule de germanium et d'alliage de germanium et procede de realisation associe Withdrawn EP1756335A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10/849,536 US20050072679A1 (en) 1999-10-22 2004-05-19 Germanium and germanium alloy nanoparticle and method for producing the same
PCT/US2005/017063 WO2005123985A2 (fr) 1999-10-22 2005-05-16 Nanoparticule de germanium et d'alliage de germanium et procede de realisation associe

Publications (2)

Publication Number Publication Date
EP1756335A2 EP1756335A2 (fr) 2007-02-28
EP1756335A4 true EP1756335A4 (fr) 2008-08-27

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EP05785299A Withdrawn EP1756335A4 (fr) 2004-05-19 2005-05-16 Nanoparticule de germanium et d'alliage de germanium et procede de realisation associe

Country Status (3)

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EP (1) EP1756335A4 (fr)
JP (1) JP2008504448A (fr)
CN (1) CN101379222A (fr)

Families Citing this family (6)

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Publication number Priority date Publication date Assignee Title
NL2005112C2 (en) * 2010-07-19 2012-01-23 Univ Leiden Process to prepare metal nanoparticles or metal oxide nanoparticles.
CN106400058B (zh) * 2016-09-14 2018-05-29 闽南师范大学 一种水溶性锗纳米粒子的制备方法
CN107217279B (zh) * 2017-05-31 2018-10-02 东北大学 一种电解法制备金属纳米颗粒的方法
CN108411267B (zh) * 2018-04-25 2020-04-17 河南科技大学 一种制备自由态多面体纳米Ag颗粒的方法
CN109585504B (zh) 2018-10-08 2020-12-25 惠科股份有限公司 显示面板及显示面板的制作方法
CN109755332B (zh) * 2018-12-11 2020-10-16 惠科股份有限公司 一种感光器、面板和感光器的制程方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
No further relevant documents disclosed *

Also Published As

Publication number Publication date
CN101379222A (zh) 2009-03-04
EP1756335A2 (fr) 2007-02-28
JP2008504448A (ja) 2008-02-14

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