US2264464A - Method of making electrode systems - Google Patents

Method of making electrode systems Download PDF

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Publication number
US2264464A
US2264464A US282956A US28295639A US2264464A US 2264464 A US2264464 A US 2264464A US 282956 A US282956 A US 282956A US 28295639 A US28295639 A US 28295639A US 2264464 A US2264464 A US 2264464A
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United States
Prior art keywords
selenium
temperature
coating
decrease
current
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Expired - Lifetime
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US282956A
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English (en)
Inventor
Willem Christiaan Van Geel
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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Publication date
Application filed by Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D48/00—Individual devices not covered by groups H10D1/00 - H10D44/00
    • H10D48/01—Manufacture or treatment
    • H10D48/04—Manufacture or treatment of devices having bodies comprising selenium or tellurium in uncombined form
    • H10D48/043—Preliminary treatment of the selenium or tellurium, its application to foundation plates or the subsequent treatment of the combination
    • 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

Definitions

  • My invention relates to a method of making an electrode system of unsymmetrlc conductivity which commises a selenium electrode.
  • the main object of my invention is to provide an improved method by which not only the specic resistance of the selenium acquires an advantageous value, but also the electrical properties are maintained constant to a higher degree than was possible with the known method.
  • the support with the selenium applied thereto is lirst heated to a temperature slightly below the melting point of selenium and subsequently the aggregate is cooled down while under pressure.
  • Electrode systems made by. the method of the invention are less subject to the so-called aging phenomenon than are the electrode systems manufactured by the known method.
  • the term "aging phenomenon is to be understood to mean the always growing decrease in forward current with constant voltage as the electrode system becomes older. ⁇ This phenomenon has been recognized by K. Maier inzelmaschinerichter 1937, page 193, which states that blocking layer rectifiers exhibit a continuous decrease in forward current also in continuous operation. I shall hereinafter refer more fully to this phenomenon which also occurs in intermittent operation.
  • the selenium is cooled during pressing from a temperature slightly below its melting point to a temperature between about 180 C. and 140 C., preferably about 160 C., and subsequently the electrode system is cooled down to room temperature without the use of pressure.
  • pressing is meant a treatment during which the entire surface of the selenium is simultaneously subjected to a pressure which is constant and equal throughout the surface.
  • selenium is brought into its liquid state, and about 0.5% by weight of columbium .chloride (CbCl5) is added thereto while constantly stirring the mixture to obtain as ne a division as possible.
  • a quantity of this selenium mixture is applied to the surface of a suitable support, ⁇ for instance a4 plate oi aluminum, which, if desired, may previously be Toughened, zinc-plated and provided with a graphite coating, as described in the U. S. patent application S. N. 210,796 led May 28. 1938.
  • the selenium is preferably applied by centrifuging, because this method allows the selenium to be applied in the form of a very thin and uniform coating, for instance, about 0.2 mm. thick. According to this method of applying the selenium. which has been describedin detail in the U. S. patent application S. N. 254,508
  • the aluminum plate provided in the above manner with the selenium coating is then placed in an oven after the upper side o f the selenium coating has been covered with a metalor mica plate which is smeared on the selenium side with quinoline (CoH'zN) or another material which produces an alkaline reaction and has a high boiling point.
  • the aggregate is then heated for several minutes in the oven at a temperature of about 190 to 210 C., preferably at about 200 C., and is then pressed for about 5 minutes at a pressure of about kgs. per sq. cm. in a press comprising two bodies having plane surfaces so that the pressure is equally distributed over the
  • the advantages obtained by using my method 5o selenium surface The temperature of the pres is maintained at about 155 C., so that during pressing the selenium is subject to a temperature drop of about 45 C.
  • 'I'he quinoline acts upon the selenium during the heating to about 200 C. in the oven so that at that time the formation of the blocking layer is begun. While the layer is in the press, the blocking layer is strengthened and is given the thickness suitable for normal operation.
  • the selenium may remain in the press and at a temperature of 155 C., until the desired conductivity has been attained. subjected to a renewed subsequent treatment in the oven at a temperature of approximately 200 C. without applying pressure.
  • the conductive electrode still has to be applied to the blocking layer.
  • This may be effected in known manner, for example, by spraying a low-melting alloy upon the blocking layerby means of a spraying gun.
  • a spraying gun for this purpose I may use, for example, an alloy melting at about 103 C. and consisting of tin, bismuth and cadmium in a proportion by weight of 26:53:21.
  • the curves a and b represent the results obtained with two rectiflers a and b of equal dimensions.
  • the two rectiers were manufactured in the same manner except that rectifier a was pressed with an increase in temperature and the rectiier J was, in accordance with the present invention, lpressed with a decrease in temperature.
  • the two rectifiers immediately after manufacture exhibited a forward current of L1.0 amps. when a direct voltage of 2 volts was applied. After being stored for about twenty-four hours, the two rectiers were measured again in the same manner. From the curves it appears that after one day of aging rectiiier a shows a decrease in current of 1.4 amp., i. e.
  • rectifier b shows a decrease in current of 1.5 amp. i. e. a forward current of 2.5 amp.
  • Periodic measurements show that the decrease in current of the rectifier a becomes greater and greater' with an increase of age, whereas the decrease in current of the rectifier b, which initially may be greater than that of rectifier a, immediately becomes lower.
  • the aggregate may be From a comparison of the curves a and b it appears that after about 1.3 days of aging, a total aging-of the original arrear of the rectifier b with respect to a is recovered. 'I'he forward current of a decreases more and more and after about 3 months (90 days) the outgoing current is about 1.8 amp. and has consequently fallen down to a value of less than half the original outgoing current (4.0 amp.). This decrease continues, though less rapidly.
  • the steps of applying a coating of selenium to a support heating the coated support to a temperature above about 190 C. and below the melting point of the selenium, cooling the coated support to a temperature of about C. while applying pressure to the selenium coating, and cooling the coated support without applying pressure to the selenium coating.
  • an electrode system of unsymmetric conductivity the steps of applying a coating of selenium to a support, applying to the surface of the selenium coating a material adapted to produce an alkaline reaction, heating the coated support to a temperature above C. and below the melting point of the selenium to form a blocking layer by the action of said material on the selenium coating, cooling the coated support from said temperature while applying pressure to the selenium coating, and cooling the coated support to room temperature in the absence of pressure.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
  • Photoreceptors In Electrophotography (AREA)
US282956A 1938-07-29 1939-07-05 Method of making electrode systems Expired - Lifetime US2264464A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEP0002132 1938-07-29

Publications (1)

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US2264464A true US2264464A (en) 1941-12-02

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US282956A Expired - Lifetime US2264464A (en) 1938-07-29 1939-07-05 Method of making electrode systems

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US (1) US2264464A (enrdf_load_stackoverflow)
CH (1) CH214486A (enrdf_load_stackoverflow)
FR (1) FR858320A (enrdf_load_stackoverflow)
GB (1) GB531580A (enrdf_load_stackoverflow)
NL (2) NL94534B (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2446466A (en) * 1944-11-11 1948-08-03 Fansteel Metallurgical Corp Blocking layer rectifier
US2468003A (en) * 1941-07-24 1949-04-19 Hartford Nat Bank & Trust Co Method of manufacturing a selenium blocking-layer cell

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2468003A (en) * 1941-07-24 1949-04-19 Hartford Nat Bank & Trust Co Method of manufacturing a selenium blocking-layer cell
US2446466A (en) * 1944-11-11 1948-08-03 Fansteel Metallurgical Corp Blocking layer rectifier

Also Published As

Publication number Publication date
GB531580A (en) 1941-01-07
FR858320A (fr) 1940-11-22
NL94534B (enrdf_load_stackoverflow) 1900-01-01
CH214486A (de) 1941-04-30
NL54463C (enrdf_load_stackoverflow) 1900-01-01

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