US2193610A - Selenium contact electrode - Google Patents

Selenium contact electrode Download PDF

Info

Publication number
US2193610A
US2193610A US190995A US19099538A US2193610A US 2193610 A US2193610 A US 2193610A US 190995 A US190995 A US 190995A US 19099538 A US19099538 A US 19099538A US 2193610 A US2193610 A US 2193610A
Authority
US
United States
Prior art keywords
selenium
contact electrode
electrode
rectifier
cadmium
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.)
Expired - Lifetime
Application number
US190995A
Inventor
Earl D Wilson
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.)
CBS Corp
Original Assignee
Westinghouse Electric and Manufacturing Co
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
Application filed by Westinghouse Electric and Manufacturing Co filed Critical Westinghouse Electric and Manufacturing Co
Priority to US190995A priority Critical patent/US2193610A/en
Priority to FR849690D priority patent/FR849690A/en
Application granted granted Critical
Publication of US2193610A publication Critical patent/US2193610A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/06—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials
    • H01L21/14—Treatment of the complete device, e.g. by electroforming to form a barrier
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02518—Deposited layers
    • H01L21/02521—Materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02656—Special treatments
    • H01L21/02664—Aftertreatments
    • H01L21/02667—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/06—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials
    • H01L21/10—Preliminary treatment of the selenium or tellurium, its application to the foundation plate, or the subsequent treatment of the combination
    • H01L21/103—Conversion of the selenium or tellurium to the conductive state
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/06—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials
    • H01L21/12—Application of an electrode to the exposed surface of the selenium or tellurium after the selenium or tellurium has been applied to the foundation plate

Definitions

  • My invention relates to dry rectiflers and especially to the selenium dry rectifier.
  • An object of the invention is to provide a very efiicient selenium rectifier.
  • Another object of the invention is to provide a very intimate contact by electrodes'to the rectifying layer of selenium.
  • Another object is to provide a method of reducing the reverse current in selenium rectifiers.
  • I preferably take as an electrode a material of the iron group, and particularly a plate of cold rolled steel such as that illustrated in cross-section in the drawing.
  • One surface of this electrode is roughened to a go mat surface by any convenient process such as sand blasting or acid etching.
  • I coat the rectifying layer which may be any one or combination of the selenium or sulphur group.
  • I prefer, however, to coat the roughened surface of the plate with amorphous selenium at a temperature between 220C. and 250C. and to apply the selenium to a thickness of several mils and to cool it quickly.
  • This selenium is preferably of a commercially available quality having the highest order of electrical conductance when in the metallic form.
  • the coated steel plate is then preferably heated to approximately 130 C. and is pressed against a smooth flat surface with sufficient force to reduce the plastic selenium to a smooth uniform layer preferably about two mils thick.
  • This smooth flat surface may be conveniently provided by the use of a phenol condensation product, H especially that sold under the trade name of "MicartaJ'
  • H phenol condensation product
  • the plate is then put preferably into” an oven at room temperature and heated gradually to approximately 180 to 190 C. within a period of two hours, after which it is annealed at the acquired temperature for several hours, I' preferably at least six. In practice, this can be Conveniently done overnight.
  • the oven is then preferably gradually cooled to room temperature before the plate is removed, the time taken being preferably that of three hours.
  • a preferred cadmium alloy is that of the eutectic of cadmium and tin which is approximately '75% tin and 25% cadmium with a melting point about 165 C.
  • the percentage of cadmium may be varied from 100% or all cadmium to that of a small percentage, for example 0.1% with the tin.
  • a typical element made as specified will deliver about amperes per square inch in the forward direction at 3 volts, and about .03 ampere for the same voltage in the reverse direction.
  • the reverse current can be still further reduced by applying suificient alternating-current voltage to the element to bring the temperature momentarily to approximately 150 to 175 ⁇ C. Repeated applicatons of this treatment may reduce the reverse current by a factor of 5 or with only a relatively slight decrease in forward conductance.
  • the method of reducing the back current in a selenium rectifier which comprises applying sufl'icient alternating-current voltage thereto to bring the temperature momentarily to approximately 150 to 175 C.

Description

March 1940. E. D. wLsoN V 2,193,610
y SELENIUM CONTACT ELECTRODE Filed Feb. 17, 1938 /l/l//I/l/l///I/I/I//I/l/ m (wwseleniun ATTORN I Patented Mar. 12, 1940 UNITED STATES SELENIUM CONTACT ELECTRODE Earl D. Wilson, Wilkinsburg, Pa., assignor to Westinglouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation oi' Pennsylvania Application February 17, 1938, Serial No. 190395 1 Claim.
My invention relates to dry rectiflers and especially to the selenium dry rectifier.
An object of the invention is to provide a very efiicient selenium rectifier.
Another object of the invention is to provide a very intimate contact by electrodes'to the rectifying layer of selenium.
Another object is to provide a method of reducing the reverse current in selenium rectifiers.
Other objects and advantages of the invention will be apparent from the following description and drawing, in which the figure is a cross-section through a preferred type of rectifier embodying the invention.
u In forming the rectifier, I preferably take as an electrode a material of the iron group, and particularly a plate of cold rolled steel such as that illustrated in cross-section in the drawing. One surface of this electrode is roughened to a go mat surface by any convenient process such as sand blasting or acid etching. Upon this surface I coat the rectifying layer which may be any one or combination of the selenium or sulphur group. I prefer, however, to coat the roughened surface of the plate with amorphous selenium at a temperature between 220C. and 250C. and to apply the selenium to a thickness of several mils and to cool it quickly. This selenium is preferably of a commercially available quality having the highest order of electrical conductance when in the metallic form.
The coated steel plate is then preferably heated to approximately 130 C. and is pressed against a smooth flat surface with sufficient force to reduce the plastic selenium to a smooth uniform layer preferably about two mils thick. This smooth flat surface may be conveniently provided by the use of a phenol condensation product, H especially that sold under the trade name of "MicartaJ' The plate is then put preferably into" an oven at room temperature and heated gradually to approximately 180 to 190 C. within a period of two hours, after which it is annealed at the acquired temperature for several hours, I' preferably at least six. In practice, this can be Conveniently done overnight. The oven is then preferably gradually cooled to room temperature before the plate is removed, the time taken being preferably that of three hours.
In order to provide an intimate contact with the other electrode thereon, I prefer to `spray the material of the other electrode onto the selenium surface. I have discovered that cadmium in the sprayed electrode contributes towards the formation of a rectifying layer between the selenium and the electrode coating thereon. A preferred cadmium alloy is that of the eutectic of cadmium and tin which is approximately '75% tin and 25% cadmium with a melting point about 165 C. The percentage of cadmium may be varied from 100% or all cadmium to that of a small percentage, for example 0.1% with the tin.
A typical element made as specified will deliver about amperes per square inch in the forward direction at 3 volts, and about .03 ampere for the same voltage in the reverse direction.
I have also discovered that the reverse current can be still further reduced by applying suificient alternating-current voltage to the element to bring the temperature momentarily to approximately 150 to 175`C. Repeated applicatons of this treatment may reduce the reverse current by a factor of 5 or with only a relatively slight decrease in forward conductance.
Many modifications may be made in the form and arrangement of the parts disclosed in the rectifier, and also various modifications may be made in the various steps and temperatures in forming the selenium rectifier. Accordingly, I desire only such limitations to be imposed upon the following claim as is necessitated by the prior art.
I claim as my invention:
The method of reducing the back current in a selenium rectifier which comprises applying sufl'icient alternating-current voltage thereto to bring the temperature momentarily to approximately 150 to 175 C.
EARL D. WIISON.
US190995A 1938-02-17 1938-02-17 Selenium contact electrode Expired - Lifetime US2193610A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US190995A US2193610A (en) 1938-02-17 1938-02-17 Selenium contact electrode
FR849690D FR849690A (en) 1938-02-17 1939-01-31 Improvements to selenium electrodes for electric rectifiers

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US190995A US2193610A (en) 1938-02-17 1938-02-17 Selenium contact electrode

Publications (1)

Publication Number Publication Date
US2193610A true US2193610A (en) 1940-03-12

Family

ID=22703675

Family Applications (1)

Application Number Title Priority Date Filing Date
US190995A Expired - Lifetime US2193610A (en) 1938-02-17 1938-02-17 Selenium contact electrode

Country Status (2)

Country Link
US (1) US2193610A (en)
FR (1) FR849690A (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2457169A (en) * 1945-03-12 1948-12-28 Standard Telephones Cables Ltd Method of manufacturing of rectifier elements
US2459848A (en) * 1945-05-12 1949-01-25 Standard Telephones Cables Ltd Rectifier element
US2488369A (en) * 1943-12-15 1949-11-15 Westinghouse Electric Corp Selenium rectifier
US2496692A (en) * 1947-03-20 1950-02-07 Westinghouse Electric Corp Selenium rectifier
US2497649A (en) * 1946-07-31 1950-02-14 Gen Electric Process of electroforming selenium rectifiers
US2510322A (en) * 1945-09-22 1950-06-06 Union Switch & Signal Co Selenium rectifier
US2585014A (en) * 1942-07-02 1952-02-12 Standard Telephones Cables Ltd High-voltage rectifier disk
US2747254A (en) * 1952-06-14 1956-05-29 Westinghouse Electric Corp Manufacture of selenium rectifiers
US2842830A (en) * 1953-10-02 1958-07-15 Int Standard Electric Corp Process for the manufacture of selenium rectifier
US2915687A (en) * 1953-12-01 1959-12-01 Itt Electroforming of semiconductive cells
US3002135A (en) * 1958-06-11 1961-09-26 Hughes Aircraft Co Semiconductor device
DE975845C (en) * 1951-12-20 1962-10-25 Standard Elek K Lorenz Ag Process for the production of selenium rectifier plates with a multilayer cover electrode

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2585014A (en) * 1942-07-02 1952-02-12 Standard Telephones Cables Ltd High-voltage rectifier disk
DE884847C (en) * 1943-12-15 1953-07-30 Westinghouse Electric Corp Dry contact rectifier or light-sensitive element
US2488369A (en) * 1943-12-15 1949-11-15 Westinghouse Electric Corp Selenium rectifier
US2457169A (en) * 1945-03-12 1948-12-28 Standard Telephones Cables Ltd Method of manufacturing of rectifier elements
US2459848A (en) * 1945-05-12 1949-01-25 Standard Telephones Cables Ltd Rectifier element
US2510322A (en) * 1945-09-22 1950-06-06 Union Switch & Signal Co Selenium rectifier
US2497649A (en) * 1946-07-31 1950-02-14 Gen Electric Process of electroforming selenium rectifiers
US2496692A (en) * 1947-03-20 1950-02-07 Westinghouse Electric Corp Selenium rectifier
DE975845C (en) * 1951-12-20 1962-10-25 Standard Elek K Lorenz Ag Process for the production of selenium rectifier plates with a multilayer cover electrode
US2747254A (en) * 1952-06-14 1956-05-29 Westinghouse Electric Corp Manufacture of selenium rectifiers
US2842830A (en) * 1953-10-02 1958-07-15 Int Standard Electric Corp Process for the manufacture of selenium rectifier
US2915687A (en) * 1953-12-01 1959-12-01 Itt Electroforming of semiconductive cells
US3002135A (en) * 1958-06-11 1961-09-26 Hughes Aircraft Co Semiconductor device

Also Published As

Publication number Publication date
FR849690A (en) 1939-11-29

Similar Documents

Publication Publication Date Title
US2193610A (en) Selenium contact electrode
US2364642A (en) Method of making selenium elements
US3173202A (en) Aluminum cladding
US2934480A (en) Titanium coating and method of forming same
US2815475A (en) Selenium rectifier
US2303869A (en) Treatment of metals
US2279187A (en) Alternating electric current rectifier of the selenium type
US2364436A (en) Insulation for magnetic steel and the like
US2334554A (en) Method of producing blocking layer devices
US2124306A (en) Electrical device
US2524270A (en) Selenium rectifier
US2745047A (en) Selenium rectifiers and method of manufacture
US2261725A (en) Selenium rectifier
US2610386A (en) Semiconductive cell
US2554237A (en) Rectifier
US2479446A (en) Method of manufacturing small current selenium rectifiers
US2390771A (en) Selenium rectifier
US2229807A (en) Method of manufacturing selenium rectifiers
US2195231A (en) Art of coating metals
US1813657A (en) Method of and apparatus for soldering
US2221614A (en) Method of manufacturing selenium rectifiers
US2555247A (en) Semiconductive cell
US2195725A (en) Method of manufacturing selenium rectifiers
US2496692A (en) Selenium rectifier
US1565495A (en) Process by which aluminum metal and its alloys may be applied to ferrous metal