US2659682A - Apparatus and method for making a photoconductive element - Google Patents

Apparatus and method for making a photoconductive element Download PDF

Info

Publication number
US2659682A
US2659682A US42679A US4267948A US2659682A US 2659682 A US2659682 A US 2659682A US 42679 A US42679 A US 42679A US 4267948 A US4267948 A US 4267948A US 2659682 A US2659682 A US 2659682A
Authority
US
United States
Prior art keywords
tube
cell
envelope
photo
support
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
US42679A
Inventor
Norman C Anderson
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.)
Continental Electric Co
Original Assignee
Continental Electric 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 Continental Electric Co filed Critical Continental Electric Co
Priority to US42679A priority Critical patent/US2659682A/en
Application granted granted Critical
Publication of US2659682A publication Critical patent/US2659682A/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
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors

Definitions

  • This invention relates to improvements in photo-electric cells, particularly of the photoconductive type.
  • the object of this invention is to improve the construction and method of making photoelectric cells of the photoco'nductive type byproviding for the manufacture of such cells with favorable characteristics in great quantities uhdercontrolled conditions.
  • Fig. l is a perspective view of the photo-electric cell made in accordance with this invention.
  • Fig. 2 is a sectiona1 view through the exhaust and activation device for the cell.
  • Fig. 3 is a diagrammatic view of the exhaust system.
  • This invention utilizes the principle there described and has reference particularly to the method of depositing and activating a photo sensitive surface on the inside of the tube, with reference especially to the photoconductive type of surface.
  • the cells comprises an envelope or tube generally designated at I,initially formed of a glass cylinder, preferably made of lime or lead glass.
  • the tube I is provided with a press 2, on'one end thereof, which seals said end and also seals thelead-in connections or conductors for the tube, Extending into the lower end of the press 2, are two or more conductors 3, composed of an outer lead, preferably of nickel, and an intermediate wire or piece of metal designated at I, having the same expansion plied to each termina1 on the inside wall of the tube I, adjacent the conductors 4, to which the latter are connected.
  • a silver paint combined with a binder and havin good conductivity, which binder usually is composed 'of 'an organic;compound which will bake out at a relatively low temperature and thus be, decomposed.
  • a. silver paint sold under the trade name Dupont No. 4810 has the property of baking out at a temperature of 300 C. and to be very suitable for this purpose.
  • a suitable conductive material such as carbon or platinum is applied in the form of a strip 6, on opposite sides, or diflerent sides, to the inside wall of the tube I.
  • This material may be applied by a ruling pen and extends from the paste of silver paint 5, with which it is in contact, to the photo-sensitive surface I on the inside of the tube I.
  • the tube is then submitted to a baking process, and when aquadag is used by a gradual increase in temperature to 300 C as the electrode material, this is accomplished
  • An exhaust tube 8 is then sealed onto the outer end of the tube I, and the cell is thus prepared aesaoee 25 C. for approximately fifteen minutes.
  • Quartz cylinders which have been previously thoroughly cleaned by immersion in dilute hydrofluoric acid and subsequent heating, are introduced in the solution on a suitable holder immediately after mixing. After deposition of a coating the cylinders are dried in air and the procedure is repeated until a coating of suitable thickness has been obtained, which is, in averagefthe case after three treatments. The cylinders are heated in air at a temperature between 120 C. and 700 C., and are ready for further operation.
  • This step of manufacturing can be modified by the use of cylinders on which the material instead of being chemically deposited has been evaporated from natural galena or chemical lead sulfide at temperatures of approximately 400 C. on cylinders and air pressure of approximately 200 microns. It is to be here understood that suitable compounds of other semi-conductive material containing thallium, silver, oxygen, selenium, tellurium and the like may be substituted for the thioreau and lead acetate.
  • a cylinder as thus prepared is designated generally at 9, in Fig. 2, with the coating thereon designated It).
  • This cylinder is shown as mounted over a heating coil H, preferably formed of platinum or other good conductor, and connected through terminals It, to a source of electric supply which can be regulated by a resistor or a variac, the voltage being indicated on a voltmeter
  • the prepared blank is slipped over the refractory cylinder 9, with the deposited material l thereon, so that the terminals of the conducting strips are opposite the cylinder.
  • the outer end of the exhaust tube 8. has a vacuum-tight contact with a piece of cushion material capable of withstanding high temperatures, such as silicone rubber indicated at It, so the inside of the tube can be evacuated through a manifold generally indicated in Fig.
  • the manifold l 5 may be provided with a stop cock l1, and a connection It, adapted to extend to a vacuum gauge, and also may have an additional connection I 9, to extend to a Pirani gauge.
  • a plurality of blanks may be treated simultaneously, all of which are mounted in side-by-slde relation on a support generally designated at 20, forming a cover over a hood 2
  • a plate 23 is also connected with the support 20, and carries upstanding rods 24 upon which is slidably mounted a heating oven generally designated at 25.
  • the oven 25 contains a heating coil 26 therein, adapted to be connected through a power line 21 to a source of electric supply.
  • This oven preferably is made of glass or other transparent material, so as to observe the treatment of the blanks.
  • the oven 25 is raised, and the cells are cooled to room temperature.
  • the manifold is is shut off from the vacuum pump 16; air is introduced into the system; and the cell or cells can be removed from the individual seats I d.
  • the tubes are then introduced to another manifold where they are exhausted to a pressure below microns of air and the exhaust tubes 8 are sealed off, and the tube is then sealed at 29. thus making the cell a vacuum-tight cell device.
  • This last procedure may be omitted on certain types of cells by sealing off tubes at gas pressures up to atmospheric pressure if desired.
  • a support having an upstanding support thereon adapted to receive a layer of semi-conductive material thereon, a cushion surrounding the upstanding support in position for sealing engagement with an exhaust tube on an envelope, upstanding guides carried by the first-mentioned support, an oven slidablymounted on the guides for lowering movement over the envelope, and heating means in the upstanding support.
  • a support having an upstanding support thereon adapted to receive a layer of semi-conductive material thereon, upstanding guides carried by the first mentioned support, an oven slidably mounted on the guides for lowering movement over the envelope, and heating means in the oven for heating the material on the support.
  • a support having an upstanding support thereon adapted to receive a layer of semi-conductive material thereon, a cushion surrounding the upstanding support in position for sealing engagement with an exhaust tube on an envelope, upstanding guides carried by the first-mentioned support.
  • an oven slidably mounted on the guides for lowering movement over the envelope. and means in the oven for heating the material on' the support.
  • a method of making a photo-conductive tube included an envelope comprising depositing a layer of lead sulphide on a supporting surface, introducing the lead sulphide on said surface into the envelope, and transferring the lead sulphide by evaporation from the surface onto the envelope while activating said lead sulphide by heating said surface to a temperature between 250 Grand 450 C.
  • a method of making a photo-conductive tube including an envelope comprising depositing a layer of lead sulphide on a supporting surface, introducing the lead sulphide on said surface into the envelope, and transferring the lead sulphide by evaporation from the surface onto the envelope while activating said lead sulphide by heating said surface to a temperature between 250 C. and 450 C. in an atmosphere of between 1 and 60 mm. of mercury.
  • a cylindrical support adapted to receive a layer of semi-conductive material thereon and to have the cell telescoped thereover, an electric heating element within the cylindrical support for evaporating the material therefrom onto the cell, and an oven for heating the cell.
  • a cylindrical support adapted to receive a layer of semi-conductive material thereon and to have the cell telescoped thereover, an electric heating element within the cylindrical support for evaporating the material therefrom onto the cell, means for supporting the cell over the support, an oven for surrounding the cell, and heating means in the oven.

Description

2,659,682 zms M N E 00 m Emw DT Mum c m Nov. 17, 1953 N APPARATUS A PHO'I 2 Sheets-Sheet 1 Filed Aug. 5, 1948 f. If
NDRMAN E. ANDERSON Nov. 17, 1953 C ANDERSON 2,659,682
APPARATUS AND METHOD FOR MAKING A PHOTOCONDUCTIVE ELEMENT Filed Aug. 5, L948 2 Sheets-Sheet 2 #1 4 '11 m E 1 m L5 2 m I:
A I; n
u R I m U F l 8 5 swam M NURMAN [l ANDERSON wag Patented Nov. 17, 1953 APPARATUS AND METHOD FOR MAKING A PHOTOCONDUCTIVE ELEItIENT Norman C. Anderson, Batavia, Ill., asslgnor to Continental Electric Company, Geneva, 11]., a
corporation of Delaware Application August 5, 1948, Serial No. 42,679
' 7 Claims. (01. 117-97) This invention relates to improvements in photo-electric cells, particularly of the photoconductive type.
It has been proposed heretofore to provide photo-electric cells using lead sulphide for the conductive elements, but such proposals have not been entirely satisfactory due to dimc'ulties of forming the cells.
The object of this invention'is to improve the construction and method of making photoelectric cells of the photoco'nductive type byproviding for the manufacture of such cells with favorable characteristics in great quantities uhdercontrolled conditions.
One embodiment of the process of this invention, and the apparatus used in connection therewith, is illustrated in the accompanying drawings, in which:
Fig. l is a perspective view of the photo-electric cell made in accordance with this invention;
Fig. 2 is a sectiona1 view through the exhaust and activation device for the cell; and
Fig. 3 is a diagrammatic view of the exhaust system.
In the copending application of Gerhard Lewin and John Benes, Jr., for Photo-Electric Tubes, Serial No. 743,040, iiied April 22, 1947 and now Patent No. 2,537,225, is set forth a process of making a photo-electric cell. This method consistedof cutting a piece of glass tubing to length, making a press on one end of the glass tube with two protruding rigid lead wires forming the electric conductors for the photo-sensitive surface and located on the outside of the press, depositing the photo-sensitive material on the inside of the tube, sealing on of anexhaust tube to the other end of the glass tube, and, activating and exhausting said photo-electric material.
This invention utilizes the principle there described and has reference particularly to the method of depositing and activating a photo sensitive surface on the inside of the tube, with reference especially to the photoconductive type of surface.
In this type of surface the resistance of a semi-conductive material is reversibly changed b impinging radiation; Materials having this property are well-known and particularly compounds of the group comprising lead, thallium, and silver in combination with one or more of the group comprising oxygen, sulphur, selenium, and tellurium show the desired properties. While the process is described in connection with photo-electric cells having a sensitive surface composed of lead, sulphur and oxygen, it will be understood that the same process can be applied to other materials mentioned above.
Referring to Fig. 1, the cells comprises an envelope or tube generally designated at I,initially formed of a glass cylinder, preferably made of lime or lead glass. The tube I is provided with a press 2, on'one end thereof, which seals said end and also seals thelead-in connections or conductors for the tube, Extending into the lower end of the press 2, are two or more conductors 3, composed of an outer lead, preferably of nickel, and an intermediate wire or piece of metal designated at I, having the same expansion plied to each termina1 on the inside wall of the tube I, adjacent the conductors 4, to which the latter are connected. It is preferred to use a silver paint combined with a binder and havin good conductivity, which binder usually is composed 'of 'an organic;compound which will bake out at a relatively low temperature and thus be, decomposed. I have found that a. silver paint sold under the trade name Dupont No. 4810, has the property of baking out at a temperature of 300 C. and to be very suitable for this purpose.
Next a suitable conductive material, such as carbon or platinum is applied in the form of a strip 6, on opposite sides, or diflerent sides, to the inside wall of the tube I. This material may be applied by a ruling pen and extends from the paste of silver paint 5, with which it is in contact, to the photo-sensitive surface I on the inside of the tube I. The tube is then submitted to a baking process, and when aquadag is used by a gradual increase in temperature to 300 C as the electrode material, this is accomplished An exhaust tube 8 is then sealed onto the outer end of the tube I, and the cell is thus prepared aesaoee 25 C. for approximately fifteen minutes. Quartz cylinders which have been previously thoroughly cleaned by immersion in dilute hydrofluoric acid and subsequent heating, are introduced in the solution on a suitable holder immediately after mixing. After deposition of a coating the cylinders are dried in air and the procedure is repeated until a coating of suitable thickness has been obtained, which is, in averagefthe case after three treatments. The cylinders are heated in air at a temperature between 120 C. and 700 C., and are ready for further operation.
This step of manufacturing can be modified by the use of cylinders on which the material instead of being chemically deposited has been evaporated from natural galena or chemical lead sulfide at temperatures of approximately 400 C. on cylinders and air pressure of approximately 200 microns. It is to be here understood that suitable compounds of other semi-conductive material containing thallium, silver, oxygen, selenium, tellurium and the like may be substituted for the thioreau and lead acetate.
A cylinder as thus prepared is designated generally at 9, in Fig. 2, with the coating thereon designated It). This cylinder is shown as mounted over a heating coil H, preferably formed of platinum or other good conductor, and connected through terminals It, to a source of electric supply which can be regulated by a resistor or a variac, the voltage being indicated on a voltmeter The prepared blank is slipped over the refractory cylinder 9, with the deposited material l thereon, so that the terminals of the conducting strips are opposite the cylinder. The outer end of the exhaust tube 8. has a vacuum-tight contact with a piece of cushion material capable of withstanding high temperatures, such as silicone rubber indicated at It, so the inside of the tube can be evacuated through a manifold generally indicated in Fig. 3, at I5, by a vacuum pump IS. The manifold l 5 may be provided with a stop cock l1, and a connection It, adapted to extend to a vacuum gauge, and also may have an additional connection I 9, to extend to a Pirani gauge.
As indicated in Fig. 3, a plurality of blanks may be treated simultaneously, all of which are mounted in side-by-slde relation on a support generally designated at 20, forming a cover over a hood 2|, connected with the exhaust manifold l5 through a tube 22.
A plate 23 is also connected with the support 20, and carries upstanding rods 24 upon which is slidably mounted a heating oven generally designated at 25. This forms a practical method of treating a considerable number of blanks simultaneously, thereby facilitating the manufacture of the cells. The oven 25 contains a heating coil 26 therein, adapted to be connected through a power line 21 to a source of electric supply.
This oven preferably is made of glass or other transparent material, so as to observe the treatment of the blanks.
When the oven has been lowered over the blanks, temperature therein is raised by a coil 26 to approximately 250 C.-450 0., and the quartz. cylinders 9 are heated progressively by electric current passing through the heaters ll until the material l0, deposited on the cylinders 9, starts to evaporate. A variable leak 28 has been opened by a stop cock in the manifold I5, and air pressure in the system is read on a vacuum gauge connected therewith. This air pressure should be between 1 and 60 mm. oi mercury. The evaporation continues until approximately all of the photo-sensitive material has been deposited at 1 on the inside wall of the tube I. as may be determined by observation.
After the sensitive material has been deposited, the oven 25 is raised, and the cells are cooled to room temperature. The manifold is is shut off from the vacuum pump 16; air is introduced into the system; and the cell or cells can be removed from the individual seats I d.
The tubes are then introduced to another manifold where they are exhausted to a pressure below microns of air and the exhaust tubes 8 are sealed off, and the tube is then sealed at 29. thus making the cell a vacuum-tight cell device. This last procedure may be omitted on certain types of cells by sealing off tubes at gas pressures up to atmospheric pressure if desired.
The process described allows for the manufacture of photoelectric cells with favorable characteristics in great quantities under controlled conditions.
While the invention has been illustrated and described in one embodiment, it is recognized that variations and changes may be made therein, without departing from the invention, except as specified in the claims.
I claim:
1. In apparatus for manufacturing a photoconductive cell, the combination of a support having an upstanding support thereon adapted to receive a layer of semi-conductive material thereon, a cushion surrounding the upstanding support in position for sealing engagement with an exhaust tube on an envelope, upstanding guides carried by the first-mentioned support, an oven slidablymounted on the guides for lowering movement over the envelope, and heating means in the upstanding support.
2. In apparatus for manufacturing a photoconductive cell, the combination of a support having an upstanding support thereon adapted to receive a layer of semi-conductive material thereon, upstanding guides carried by the first mentioned support, an oven slidably mounted on the guides for lowering movement over the envelope, and heating means in the oven for heating the material on the support.
3. In apparatus for manufacturing a photo.- conductive cell, the combination of a support having an upstanding support thereon adapted to receive a layer of semi-conductive material thereon, a cushion surrounding the upstanding support in position for sealing engagement with an exhaust tube on an envelope, upstanding guides carried by the first-mentioned support. an oven slidably mounted on the guides for lowering movement over the envelope. and means in the oven for heating the material on' the support.
4. A method of making a photo-conductive tube included an envelope, comprising depositing a layer of lead sulphide on a supporting surface, introducing the lead sulphide on said surface into the envelope, and transferring the lead sulphide by evaporation from the surface onto the envelope while activating said lead sulphide by heating said surface to a temperature between 250 Grand 450 C.
5. A method of making a photo-conductive tube including an envelope, comprising depositing a layer of lead sulphide on a supporting surface, introducing the lead sulphide on said surface into the envelope, and transferring the lead sulphide by evaporation from the surface onto the envelope while activating said lead sulphide by heating said surface to a temperature between 250 C. and 450 C. in an atmosphere of between 1 and 60 mm. of mercury.
6. In apparatus for manufacturing a photoconductive cell, the combination of a cylindrical support adapted to receive a layer of semi-conductive material thereon and to have the cell telescoped thereover, an electric heating element within the cylindrical support for evaporating the material therefrom onto the cell, and an oven for heating the cell. A
7. In apparatus for manufacturing a, photoconductive cell, the combination of a cylindrical support adapted to receive a layer of semi-conductive material thereon and to have the cell telescoped thereover, an electric heating element within the cylindrical support for evaporating the material therefrom onto the cell, means for supporting the cell over the support, an oven for surrounding the cell, and heating means in the oven.
NORMAN C. ANDERSON.
References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

  1. 4. A METHOD OF MAKING A PHOTO-CONDUCTIVE TUBE INCLUDED AN ENVELOPE, COMPRISING DEPOSITING A LAYER OF LEAD SULPHIDE ON A SUPPORTING SURFACE, INTRODUCING THE LEAD SULPHIDE ON SAID SURFACE INTO THE ENVELOPE, AND TRANSFERRING THE LEAD SULPHIDE BY EVAPORATION FROM THE SURFACE ONTO THE ENVELOPE WHILE ACTIVATING SAID LEAD SULPHIDE BY
US42679A 1948-08-05 1948-08-05 Apparatus and method for making a photoconductive element Expired - Lifetime US2659682A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US42679A US2659682A (en) 1948-08-05 1948-08-05 Apparatus and method for making a photoconductive element

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US42679A US2659682A (en) 1948-08-05 1948-08-05 Apparatus and method for making a photoconductive element

Publications (1)

Publication Number Publication Date
US2659682A true US2659682A (en) 1953-11-17

Family

ID=21923194

Family Applications (1)

Application Number Title Priority Date Filing Date
US42679A Expired - Lifetime US2659682A (en) 1948-08-05 1948-08-05 Apparatus and method for making a photoconductive element

Country Status (1)

Country Link
US (1) US2659682A (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2809132A (en) * 1955-05-03 1957-10-08 Philips Corp Method of coating a support with a lead sulphide layer
US2839645A (en) * 1954-06-14 1958-06-17 Clairex Corp Photocell structure
US2876142A (en) * 1955-01-05 1959-03-03 Philips Corp Photo-electric cell
US2892250A (en) * 1954-11-03 1959-06-30 Hupp Corp Method of producing photocells
US2976419A (en) * 1953-09-14 1961-03-21 Brinro Ltd S A Apparatus for detecting sources of infra-red rays
US3030236A (en) * 1956-12-21 1962-04-17 Eastman Kodak Co Method of forming a photosensitive layer of lead sulfide crystals on a glass plate
US3032731A (en) * 1956-10-01 1962-05-01 Dresser Ind Photoconductive device and method of producing same
US3148084A (en) * 1961-08-30 1964-09-08 Ncr Co Process for making conductive film
US3178312A (en) * 1959-01-02 1965-04-13 Santa Barbara Res Ct Solutions and methods for depositing lead selenide
US3261708A (en) * 1958-07-30 1966-07-19 Eastman Kodak Co Process for forming chemically deposited photosensitive lead sulfide layers
US4097775A (en) * 1955-08-04 1978-06-27 Rca Corporation Infrared sensitive photoconductive pickup tube

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US541929A (en) * 1895-07-02 Incandescent electric lamp
US2066878A (en) * 1928-09-25 1937-01-05 Rca Corp Photoelectric tube and process of making it
US2161458A (en) * 1935-05-29 1939-06-06 Philips Nv Luminescent screen
US2401737A (en) * 1942-03-14 1946-06-11 Rca Corp Phototube and method of manufacture
US2411522A (en) * 1944-12-16 1946-11-26 Standard Telephones Cables Ltd Preparation of electrodes
US2413442A (en) * 1944-01-28 1946-12-31 Gen Electric Electrode activation
US2431923A (en) * 1943-08-23 1947-12-02 Rca Corp Photographic record and method of forming same
US2448516A (en) * 1945-08-01 1948-09-07 Univ Northwestern Photocell of lead sulfide
US2448518A (en) * 1944-04-07 1948-09-07 Univ Northwestern Photocell

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US541929A (en) * 1895-07-02 Incandescent electric lamp
US2066878A (en) * 1928-09-25 1937-01-05 Rca Corp Photoelectric tube and process of making it
US2161458A (en) * 1935-05-29 1939-06-06 Philips Nv Luminescent screen
US2401737A (en) * 1942-03-14 1946-06-11 Rca Corp Phototube and method of manufacture
US2431923A (en) * 1943-08-23 1947-12-02 Rca Corp Photographic record and method of forming same
US2413442A (en) * 1944-01-28 1946-12-31 Gen Electric Electrode activation
US2448518A (en) * 1944-04-07 1948-09-07 Univ Northwestern Photocell
US2411522A (en) * 1944-12-16 1946-11-26 Standard Telephones Cables Ltd Preparation of electrodes
US2448516A (en) * 1945-08-01 1948-09-07 Univ Northwestern Photocell of lead sulfide

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2976419A (en) * 1953-09-14 1961-03-21 Brinro Ltd S A Apparatus for detecting sources of infra-red rays
US2839645A (en) * 1954-06-14 1958-06-17 Clairex Corp Photocell structure
US2892250A (en) * 1954-11-03 1959-06-30 Hupp Corp Method of producing photocells
US2876142A (en) * 1955-01-05 1959-03-03 Philips Corp Photo-electric cell
US2809132A (en) * 1955-05-03 1957-10-08 Philips Corp Method of coating a support with a lead sulphide layer
US4097775A (en) * 1955-08-04 1978-06-27 Rca Corporation Infrared sensitive photoconductive pickup tube
US3032731A (en) * 1956-10-01 1962-05-01 Dresser Ind Photoconductive device and method of producing same
US3030236A (en) * 1956-12-21 1962-04-17 Eastman Kodak Co Method of forming a photosensitive layer of lead sulfide crystals on a glass plate
US3261708A (en) * 1958-07-30 1966-07-19 Eastman Kodak Co Process for forming chemically deposited photosensitive lead sulfide layers
US3178312A (en) * 1959-01-02 1965-04-13 Santa Barbara Res Ct Solutions and methods for depositing lead selenide
US3148084A (en) * 1961-08-30 1964-09-08 Ncr Co Process for making conductive film

Similar Documents

Publication Publication Date Title
US2659682A (en) Apparatus and method for making a photoconductive element
US3539816A (en) Contactless potentiometer using rotatable slitted cylinder
US2688564A (en) Method of forming cadmium sulfide photoconductive cells
US2161458A (en) Luminescent screen
US2448516A (en) Photocell of lead sulfide
US2879182A (en) Photosensitive devices
US2892250A (en) Method of producing photocells
US3622901A (en) Negative-temperature-coefficient resistors in the form of thin layers and method of manufacturing the same
NO152357B (en) SPORICID PREPARATION CONTAINING A Saturated DIALDEHYDE AND A DIOL
JPS58114458A (en) Method of producing thin film transistor on insulating substrate
US3434876A (en) Photosensitive cathodes
NO116423B (en)
US3203830A (en) Electrical resistor
US2448518A (en) Photocell
US2401737A (en) Phototube and method of manufacture
US2393264A (en) Photoelectric device and the manufacture thereof
US2217205A (en) Photoelectric tube
US2879184A (en) Method of rendering titanium dioxide films electrically conductive
US4034127A (en) Method of forming and treating cadmium selenide photoconductive bodies
JPH0992184A (en) Fluorescent display tube and manufacture thereof
US3114045A (en) Photo-conductive translucent electroluminescent device and method of manufacture
US3832298A (en) Method for producing a photoconductive element
US1694189A (en) Photosensitive cell
Andrew et al. A GaAs-Cs-O transmission photocathode
US3790869A (en) Humidity sensitive semiconductor device