US2386750A - Selenium cell - Google Patents

Selenium cell Download PDF

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Publication number
US2386750A
US2386750A US501532A US50153243A US2386750A US 2386750 A US2386750 A US 2386750A US 501532 A US501532 A US 501532A US 50153243 A US50153243 A US 50153243A US 2386750 A US2386750 A US 2386750A
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US
United States
Prior art keywords
selenium
lacquer
cellulose
moisture
cell
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
US501532A
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English (en)
Inventor
Saslaw Otto
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.)
STC PLC
Federal Telephone and Radio Corp
Original Assignee
Standard Telephone and Cables PLC
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 to BE461544D priority Critical patent/BE461544A/xx
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to US501532A priority patent/US2386750A/en
Priority to GB23444/44A priority patent/GB591412A/en
Priority to CH259585D priority patent/CH259585A/de
Priority to FR915811D priority patent/FR915811A/fr
Application granted granted Critical
Publication of US2386750A publication Critical patent/US2386750A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • 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
    • H01L21/02367—Substrates
    • H01L21/0237—Materials
    • H01L21/02425—Conductive materials, e.g. metallic silicides
    • 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
    • H01L21/02612—Formation types
    • H01L21/02617—Deposition types
    • H01L21/02623—Liquid deposition
    • H01L21/02625—Liquid deposition using melted 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

Definitions

  • This invention relates to selenium rectiflers and particularly to selenium cells in which the selenium layer is covered with a cellulose base lacquer. This is a continuation in part of my copending application Ser. No. 449,529, filed July 2, 1942, for Selenium cell and lacquer therefor.
  • the general purpose of this invention is to improve the voltage and rectifying characteristics of selenium cells. It includes in general the application to the selenium surface of a cellulose base lacquer and more particularly to the inclusion in the lacquer of a certain amount of moisture.
  • selenium elements are ordinarily composed of a coating of crystallized selenium on a base plate.
  • a counter electrode is applied over the selenium surface, and according to theory a blocking layer is formed under the counter electrode, thereby enabling the element to have the rectifying property of being more conductive in one direction than in the other
  • Serial Number 449.529 I have succeeded in increasing the voltage which can be applied across the cell and reducing the current flowing in the direction opposite that of normal current forward flow. I have done this by coating the metallic selenium surface, prior to application of the counter electrode, with a cellulose base lacquer, which upon drying leaves a film on the surface of the selenium.
  • FIG. 1 is a plan view of a selenium cell embodying the invention
  • Fig. 2 is a central cross section of said cell
  • Fig. 3 is a sectional diagram of a spraying apparatus for spraying humidified lacquer 0n the selenium surface in accordance with this invention.
  • Figs. 1 and 2 show a well known type of selenium disk such as is used for a rectifier. It comprises a base plate I, ordinarily of steel, on which is placed a layer of selenium 2.
  • the selenium may be applied in any suitable manner such as by melting selenium powder, spreading the molten selenium over the base plate and then allowing it to cool and harden.
  • a suitable way of carrying out this heat treatment is first to compress the selenium coated disk in a press and heat it for about a half hour at a temperature of around 120 0., then remove the pressure and raise the temperature to about 214 C. for some hours.
  • a counter electrode 4 should then be applied over the selenium layer 3. This may conveniently be done by spraying over the dried lacquer a coating of molten metallic alloy such as Wood's metal which when cooling leaves a thin metallic layer.
  • lacquers having a cellulose 'base are especially suitable for use in accordance with this invention.
  • Such lacquers include those composed in large part of regenerated cellulose,
  • cellulose esters or cellulose ethers and particu- This moisture may conveniently be aplarly those containing the lower alkyl radicals. These include cellulose formate acetate and propionate, and also methyl, ethyl and propyl cellulose. Cellulose nitrate has likewise been found to be especially effective as abase for lacquer used in the indicated manner.
  • the lacquers may be prepared in the usual manner, including a suitable volatile solvent which must be of 'a, type thatwill not have any effect On the selenium.
  • the suitable lacquer formulas are as follows.
  • Example 1 l Parts Selenium dioxide 3 Cellulose acetate lacquer. 4 Thinner All parts are by weight.
  • the cellulose acetate lacquer may be composed of four parts of jcellulose acetate dissolved in about 60 parts of methyl Cellosolve" acetate, known chemically I as ethylene glycol monopractical.
  • Example 2 Three components, A, B and C are prepared as follows: I
  • Component A is made by dissolving two parts of cellulose acetate in 60 parts of methyl Cellosolve acetate.
  • Constituent B i the thinner consisting of methyl Cellosolve acetate.
  • Constituent C is a 5% solution of the conducting material such as selenium dioxide in absolute ethyl alcohol.
  • cellulose nitrate When cellulose nitrate is used it is employed in the same proportions as cellulose acetate. It has also been found that acetone is suitabe for use as a thinner instead of some or all of the methyl Cellosolve acetate.
  • the lacquer is' applied to the selenium surface to form the layer 3 in any convenient manner as by brushing or spraying.
  • the volatilization of the thinner leaves a very thin layer of the cellulosic base mixed with the conductive material. It is desirable to make certain that the layer 3 is extremely thin, a factor which can readily be controlled by adjusting not only the amount of lacquer that is applied but also the viscosity of the lacquer. While various thinners and solvents may be employed, it is necessary that where the conductive material, such as selenium dioxide, is introduced by means of the thinner, such thinner must be a solvent of such material.
  • the solvent must be compatible with the remaining ingredients and in particular must be capable of rapid and uniform dispersion throughout the cellulosic solution. Such solvent likewise must be free from harmful action on the selenium.
  • apparatus comprises a tank 6 containing some water 8 which does not fill the tank.
  • the tank is covered by a suitable cover I to enclose the vapor.
  • An air tube 9 is led into the tank through a suitable seal l0, passes up through the water and open into the air space above the water.
  • Another tube i l is led from the air space in the tank through a seal l2 and opens into a spray chamber I3.
  • the sprayer is of an ordinary type comprising a lacquer receptacle l4 containing. the liquid lacquer l5.
  • Tube l6 dips into the lacquer and terminates at I! within the narrowed mouth i 8 of the sprayer. Compressed air is blown into the tank 6 through tube 9, and.
  • the water may be heated as by a heating element l9, and may even be boiled if a lot of moisture is desired.
  • the proper water temperature will depend somewhat upon the degree of dryness in the air at the time, and the provision of a substantial amount of moisture in the spray is especially necessary if the humidity of the surrounding atmosphere is below Under average conditions water temperatures ranging from 70 C. to 90 C. have been found to be satisfactory.
  • the air mixed with moisture passes through tube II to the sprayer where it acts upon the spray device in the usual manner to force lacquer out with the lacquer is desirable for good results.
  • the mouth of the spray together with the moisture laden air this mixes the moisture with the lacquer while it is bein applied to the selenium surface. If the moisture content of the air is sufficient the lacquer may be applied by brushing. It has been found that the moisture content should be equivalent to 50% humidity or greater; and if it is less than this amount, the air should be g'gp rly humidified to bring the humidity above After the application of the lacquer the thinner in it will volatize leaving a the base a very thin skin.- This enables the voltage applied across the element to be higher than otherwise, and reduces the current which can flow in the reverse direction. It is found that the current flowing in the forward direction is not reduced appreciably, however. Thus there is provided a selenium rectifier of high rectification ratio and high voltage breakdown quality.
  • the method of preparing a selenium cell which comprises applying to the surface of the selenium a cellulose lacquer containing moisture and an electrically conducting substance.

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  • Engineering & Computer Science (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biotechnology (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Manufacturing Of Micro-Capsules (AREA)
  • Micro-Organisms Or Cultivation Processes Thereof (AREA)
  • Paints Or Removers (AREA)
US501532A 1943-09-08 1943-09-08 Selenium cell Expired - Lifetime US2386750A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE461544D BE461544A (US06252093-20010626-C00008.png) 1943-09-08
US501532A US2386750A (en) 1943-09-08 1943-09-08 Selenium cell
GB23444/44A GB591412A (en) 1943-09-08 1944-11-24 Selenium cell and lacquer therefor
CH259585D CH259585A (de) 1943-09-08 1945-06-14 Selenzelle und Verfahren zu ihrer Herstellung.
FR915811D FR915811A (fr) 1943-09-08 1945-10-13 Redresseurs au sélénium et analogues

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US501532A US2386750A (en) 1943-09-08 1943-09-08 Selenium cell

Publications (1)

Publication Number Publication Date
US2386750A true US2386750A (en) 1945-10-16

Family

ID=23993939

Family Applications (1)

Application Number Title Priority Date Filing Date
US501532A Expired - Lifetime US2386750A (en) 1943-09-08 1943-09-08 Selenium cell

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US (1) US2386750A (US06252093-20010626-C00008.png)
BE (1) BE461544A (US06252093-20010626-C00008.png)
CH (1) CH259585A (US06252093-20010626-C00008.png)
FR (1) FR915811A (US06252093-20010626-C00008.png)
GB (1) GB591412A (US06252093-20010626-C00008.png)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2433402A (en) * 1942-07-02 1947-12-30 Standard Telephones Cables Ltd Selenium cell and lacquer therefor
US2452603A (en) * 1944-04-08 1948-11-02 Standard Telephones Cables Ltd Metal contact rectifier
US2724078A (en) * 1951-10-29 1955-11-15 Itt Selenium rectifiers
US2766157A (en) * 1953-01-15 1956-10-09 Preformed Line Products Co Method of protecting and connecting mating electrical conductor members
US2828453A (en) * 1955-06-15 1958-03-25 Westinghouse Brake & Signal Selenium rectifiers
US3204159A (en) * 1960-09-14 1965-08-31 Bramley Jenny Rectifying majority carrier device
US3704715A (en) * 1969-11-10 1972-12-05 Tamag Basel Ag Apparatus for the production of a sheet of tobacco

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2433402A (en) * 1942-07-02 1947-12-30 Standard Telephones Cables Ltd Selenium cell and lacquer therefor
US2452603A (en) * 1944-04-08 1948-11-02 Standard Telephones Cables Ltd Metal contact rectifier
US2724078A (en) * 1951-10-29 1955-11-15 Itt Selenium rectifiers
US2766157A (en) * 1953-01-15 1956-10-09 Preformed Line Products Co Method of protecting and connecting mating electrical conductor members
US2828453A (en) * 1955-06-15 1958-03-25 Westinghouse Brake & Signal Selenium rectifiers
US3204159A (en) * 1960-09-14 1965-08-31 Bramley Jenny Rectifying majority carrier device
US3704715A (en) * 1969-11-10 1972-12-05 Tamag Basel Ag Apparatus for the production of a sheet of tobacco

Also Published As

Publication number Publication date
BE461544A (US06252093-20010626-C00008.png) 1900-01-01
CH259585A (de) 1949-01-31
GB591412A (en) 1947-08-18
FR915811A (fr) 1946-11-19

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