US2449444A - Selenium rectifier - Google Patents

Selenium rectifier Download PDF

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Publication number
US2449444A
US2449444A US706758A US70675846A US2449444A US 2449444 A US2449444 A US 2449444A US 706758 A US706758 A US 706758A US 70675846 A US70675846 A US 70675846A US 2449444 A US2449444 A US 2449444A
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Prior art keywords
selenium
rectifier
barrier layer
coating
selenium rectifier
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Expired - Lifetime
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US706758A
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Wayne E Blackburn
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CBS Corp
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Westinghouse Electric Corp
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Priority to BE476528D priority Critical patent/BE476528A/xx
Priority to FR954731D priority patent/FR954731A/fr
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US706758A priority patent/US2449444A/en
Priority to GB26144/47A priority patent/GB628240A/en
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    • 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 potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/06—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a 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
    • H01L21/108—Provision of discrete insulating layers, i.e. non-genetic barrier layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
    • B01D29/114—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements arranged for inward flow filtration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B01D29/50—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition
    • B01D29/52—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in parallel connection
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B01D29/50—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition
    • B01D29/52—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in parallel connection
    • B01D29/54—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in parallel connection arranged concentrically or coaxially
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B01D29/62—Regenerating the filter material in the filter
    • B01D29/66—Regenerating the filter material in the filter by flushing, e.g. counter-current air-bumps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B01D29/76—Handling the filter cake in the filter for purposes other than for regenerating
    • B01D29/78—Handling the filter cake in the filter for purposes other than for regenerating for washing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
    • B01D29/76—Handling the filter cake in the filter for purposes other than for regenerating
    • B01D29/86—Retarding cake deposition on the filter during the filtration period, e.g. using stirrers

Definitions

  • My invention relates to selenium rectiflers and, in particular, relates to anV improved process for forming the blocking or barrier layer in such rectiers.
  • barrier layers have been produced by exposing the free surface of the selenium to lthe vapors of certain materialswhile in vacuum, by chemically treating ⁇ the seleniumsurfacegand by depositing a film of organic material on the selenium surface by dipping in a suitable solution. I'he latter has, in general. been vi'ound to be the least Y expensive but difficulty arises because films of organic material are likely to ⁇ decompose at the temperatures at which the'rectiflers are heattreated during lsubsequent steps of the manufacturing process..
  • the barrier layer thereafter comprises some carbonaceous material of uncertain composition. Furthermore, if the rectlfier is subjected to high temperatures during the subsequent operation, for example, by reason of the heat generated by losses within the rectifier itself. further decomposition of the organic material in the barrier layer occurs. Thus the maximum temperature, and hence load output of which the rectifier is capable in use is limited because such subsequent decomposition produces changes in the rectifier characteristics which cannot be tolerated.
  • One object of my present invention is to produce a barrier layer on the selenium of selenium rectiflers by a dipping process which produces an inorganic film on the free surface of the selenium.
  • Another object of my invention is to produce a selenium rectifier which is capable of'operating at higher temperatures than were selenium rectiflers of the prior art.
  • Anotherobject of my invention is'to produce .i
  • selenium 'rectifier having more stable characteristics both electrically and chemically than did selenium rectiers of the prior art.
  • Iproduce the inorganic barrier layer by coating the selenium surface with a solution or ⁇ suspension of a suitable inorganic salt in van organic liquid, and subsequently by driving olf the or- ⁇ ganic material before completion of the rectifier.
  • the preferred method ofmakixng this rectifier is .to first produce a coatingof amorphous sele- 2 nium on a. suitable base plate which may, for example, be sheet iron, sand blasted and nickel plated.
  • a sheet iron base is selenium-coated by dipping the plate in a bath of the molten selenium and throwing on excess material through centrifugal force by rotating the plate after dipping.
  • the base plate thus coated is then submerged in a hot solution or suspension of an inorganic salt-in an organic solvent.
  • uranium nitrate zirconium nitrate, magnesiumthiosulfate, gallium nitrate, zinc dithionate, potassium columbate. aluminum ni#- trate and cerous nitrate.
  • the most desirable organic solvent to be employed is alcohol or acetone.
  • the density of the salt in the solution has not been found by my experiments to date to be critical but may, for example, be that correspondling tov saturation.
  • a coating which may be cadmium or a cadmium alloy well known in the art, may then be metalsprayed onto the surface of this coating to form the counter-electrode.
  • the unit thus produced is then submitted toa heat treatment compris-l ing annealing for a period ,of about minutes at a temperature of 200 degrees centigrade. This converts'the amorphous selenium into crystalline selenium and at the same time causes the deposited film to produce the desired barrier layer.
  • the rectifier is, in accordance with a method well known in the artl subjected to electrical forming by impressing upon it an alternating voltage :of 35 volts for a period of 60 minutes. The rectifier unit is then complete.
  • a completed vrectifier thus comprises ay base plate I having on one surface a layer 2 of selenium, the free surface of the layer being covered'with a barrier layer 3 resulting from the deposition of the above-mentioned inorganic salt.
  • the free 3 face ofv the barrier layer 3 is coated 'with a counter-electrode I as above described.
  • the method o! producing a selenium rec- ⁇ tiiier which comprises ythe step of. coating the free surface of selenium with a solution of magnesium thlosulfate in alcohol.
  • the method of producing a selenium rectifier which comprises the step of coating the free ⁇ free surface of selenium with a solution of magnesium thiosulfate in acetone.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Biotechnology (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)

Description

Sept. 14,1948. w. E. BLACKBURN 2,449,444
SELENIUM RECTIFIER Filed oct. so, 1946 Wag/)7e Blac L lm.
Patented Sept. 14, 1948 2,449,444 SELENIUM nac'rmm Wayne E. Blackburn. Wilkinsburg. Pa.,
to Westinghouse Electric Corporation.
assignor East Pittsburgh, Pa., a corporation oi' Pennsylvania. Application October 30, 1946, Serial No. 706,758
4 Claims. 1 My invention relates to selenium rectiflers and, in particular, relates to anV improved process for forming the blocking or barrier layer in such rectiers. In accordancewith the prior art. such barrier layers have been produced by exposing the free surface of the selenium to lthe vapors of certain materialswhile in vacuum, by chemically treating `the seleniumsurfacegand by depositing a film of organic material on the selenium surface by dipping in a suitable solution. I'he latter has, in general. been vi'ound to be the least Y expensive but difficulty arises because films of organic material are likely to` decompose at the temperatures at which the'rectiflers are heattreated during lsubsequent steps of the manufacturing process.. The barrier layer thereafter comprises some carbonaceous material of uncertain composition. Furthermore, if the rectlfier is subjected to high temperatures during the subsequent operation, for example, by reason of the heat generated by losses within the rectifier itself. further decomposition of the organic material in the barrier layer occurs. Thus the maximum temperature, and hence load output of which the rectifier is capable in use is limited because such subsequent decomposition produces changes in the rectifier characteristics which cannot be tolerated.
One object of my present invention is to produce a barrier layer on the selenium of selenium rectiflers by a dipping process which produces an inorganic film on the free surface of the selenium. v
Another object of my invention is to produce a selenium rectifier which is capable of'operating at higher temperatures than were selenium rectiflers of the prior art.
Anotherobject of my invention is'to produce .i
a selenium 'rectifier having more stable characteristics both electrically and chemically than did selenium rectiers of the prior art.
Other objects of my invention'will becomeapparent upon reading the following specification, taken in connection with the accompanying drawing, in which the single gure is a sectional view of a rectifier embodying the principles of my invention.
In the preferred embodiment of my invention,
Iproduce the inorganic barrier layer by coating the selenium surface with a solution or `suspension of a suitable inorganic salt in van organic liquid, and subsequently by driving olf the or- `ganic material before completion of the rectifier.
The preferred method ofmakixng this rectifier is .to first produce a coatingof amorphous sele- 2 nium on a. suitable base plate which may, for example, be sheet iron, sand blasted and nickel plated. Such a sheet iron base is selenium-coated by dipping the plate in a bath of the molten selenium and throwing on excess material through centrifugal force by rotating the plate after dipping. The base plate thus coated is then submerged in a hot solution or suspension of an inorganic salt-in an organic solvent., I have found that salts which are most effective are those whose metals form stabley oxides, suliides l or selenides.
As examples of the most suitable salts, I will mention uranium nitrate, zirconium nitrate, magnesiumthiosulfate, gallium nitrate, zinc dithionate, potassium columbate. aluminum ni#- trate and cerous nitrate. The most desirable organic solvent to be employed is alcohol or acetone. The density of the salt in the solution has not been found by my experiments to date to be critical but may, for example, be that correspondling tov saturation.
After withdrawal from the bath, the solvent soon evaporates leaving a coating of the dissolved salt on the surface `of the selenium. A coating, which may be cadmium or a cadmium alloy well known in the art, may then be metalsprayed onto the surface of this coating to form the counter-electrode. The unit thus produced is then submitted toa heat treatment compris-l ing annealing for a period ,of about minutes at a temperature of 200 degrees centigrade. This converts'the amorphous selenium into crystalline selenium and at the same time causes the deposited film to produce the desired barrier layer. Thereafter the rectifier is, in accordance with a method well known in the artl subjected to electrical forming by impressing upon it an alternating voltage :of 35 volts for a period of 60 minutes. The rectifier unit is then complete.
It is my Apresent belief that the deposited inorganic salt undergesdchemical combination with the selenium on which it is deposited to form a selenide, or possibly combines with oxygen of the air to some extent. Since the exact reaction is uncertain, I will hereinafter arbitrarily refer to the combination above described as an Oxy-salt of the metal.
Referring in detail to the drawing, a completed vrectifier thus comprises ay base plate I having on one surface a layer 2 of selenium, the free surface of the layer being covered'with a barrier layer 3 resulting from the deposition of the above-mentioned inorganic salt. The free 3 face ofv the barrier layer 3 is coated 'with a counter-electrode I as above described.
I claim as my invention: v
1. The method of producing a selenium rectiner which comprises the step of coating a .free
' surface of selenium with a. suspension of magneslum thiosulfate in s. volatile organic solvent.
2. The method o! producing a selenium rec-` tiiier which comprises ythe step of. coating the free surface of selenium with a solution of magnesium thlosulfate in alcohol.
3. The method of producing a selenium rectifier which comprises the step of coating the free `free surface of selenium with a solution of magnesium thiosulfate in acetone.
REFERENCES CITED The following references are of record in the file of this patent: Y
l UNITED STATES PATENTS Number Name Date 2,137,316A van Geel et al Nov. 22. 1938 2.189.731 Do Boer et al.y Dec. 13, 1938 De Boer et al. Sept. 19. 1939
US706758A 1946-10-30 1946-10-30 Selenium rectifier Expired - Lifetime US2449444A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BE476528D BE476528A (en) 1946-10-30
FR954731D FR954731A (en) 1946-10-30
US706758A US2449444A (en) 1946-10-30 1946-10-30 Selenium rectifier
GB26144/47A GB628240A (en) 1946-10-30 1947-09-26 Improvements in or relating to selenium rectifiers

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1219591B (en) * 1962-04-07 1966-06-23 Licentia Gmbh Method for applying a uniform thallium selenide layer to the selenium layer of a rectifier

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2137316A (en) * 1935-02-06 1938-11-22 Philips Nv Electrode system and method of making same
US2139731A (en) * 1935-06-01 1938-12-13 Philips Nv Asymmetric electrode system
US2173249A (en) * 1935-10-30 1939-09-19 Philips Nv Asymmetric electrode system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2137316A (en) * 1935-02-06 1938-11-22 Philips Nv Electrode system and method of making same
US2139731A (en) * 1935-06-01 1938-12-13 Philips Nv Asymmetric electrode system
US2173249A (en) * 1935-10-30 1939-09-19 Philips Nv Asymmetric electrode system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1219591B (en) * 1962-04-07 1966-06-23 Licentia Gmbh Method for applying a uniform thallium selenide layer to the selenium layer of a rectifier

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FR954731A (en) 1950-01-05
GB628240A (en) 1949-08-24
BE476528A (en)

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