Author: D. W. READEY
Publisher:
ISBN:
Category :
Languages : en
Pages : 421
Book Description
Cadmium sulfide thin films are of interest for various electronic device applications. Films deposited on cold substrates have high conductivities unsuitable for device utilization and must be heat-treated to improve their properties. This investigation was therefore concerned with the high conductivity and phenomena resulting from heat-treatment to elucidate the mechanism that gives rise to them. Based on kinetic measurements made during heat-treatment and other experiments, it is concluded that the high conductivity is caused by a nonstoichiometric excess of cadmium in the films. During heat-treatment, the excess cadmium diffuses to the film surface where it evaporates, with diffusion being the rate-controlling mechanism. Also, the as-deposited films contain a number of electron trapping sites, most of which are annealed out during heat treatment. (Author).
Mechanism of High Conductivity in Vacuum-deposited Cadmium Sulfide Films
Author: D. W. READEY
Publisher:
ISBN:
Category :
Languages : en
Pages : 421
Book Description
Cadmium sulfide thin films are of interest for various electronic device applications. Films deposited on cold substrates have high conductivities unsuitable for device utilization and must be heat-treated to improve their properties. This investigation was therefore concerned with the high conductivity and phenomena resulting from heat-treatment to elucidate the mechanism that gives rise to them. Based on kinetic measurements made during heat-treatment and other experiments, it is concluded that the high conductivity is caused by a nonstoichiometric excess of cadmium in the films. During heat-treatment, the excess cadmium diffuses to the film surface where it evaporates, with diffusion being the rate-controlling mechanism. Also, the as-deposited films contain a number of electron trapping sites, most of which are annealed out during heat treatment. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 421
Book Description
Cadmium sulfide thin films are of interest for various electronic device applications. Films deposited on cold substrates have high conductivities unsuitable for device utilization and must be heat-treated to improve their properties. This investigation was therefore concerned with the high conductivity and phenomena resulting from heat-treatment to elucidate the mechanism that gives rise to them. Based on kinetic measurements made during heat-treatment and other experiments, it is concluded that the high conductivity is caused by a nonstoichiometric excess of cadmium in the films. During heat-treatment, the excess cadmium diffuses to the film surface where it evaporates, with diffusion being the rate-controlling mechanism. Also, the as-deposited films contain a number of electron trapping sites, most of which are annealed out during heat treatment. (Author).
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 984
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 984
Book Description
Mechanism of Cadmium Sulfide Film Cell
Author: Andrew E. Potter (Jr.)
Publisher:
ISBN:
Category : Cadmium sulfide photoconductive cells
Languages : en
Pages : 20
Book Description
Publisher:
ISBN:
Category : Cadmium sulfide photoconductive cells
Languages : en
Pages : 20
Book Description
NASA Technical Note
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 866
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 866
Book Description
Technical Abstract Bulletin
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 908
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 908
Book Description
U. S. Government Research and Development Reports
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1776
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1776
Book Description
Bibliography of Scientific and Industrial Reports
Author:
Publisher:
ISBN:
Category : Technology
Languages : en
Pages : 1698
Book Description
Publisher:
ISBN:
Category : Technology
Languages : en
Pages : 1698
Book Description
Vacuum-deposited Cadmium Sulfide Thin Films
Author: G. G. AVIS
Publisher:
ISBN:
Category : Metallic films
Languages : en
Pages : 43
Book Description
Cadmium sulfides was vacuum-deposited onto glass substrates at approximately 0.00002 torr using electron beam heating. Initial resistivities were in the range 0.1 to 1 ohm-cm. After heating in vacuum at 360 to 370C for 1/2 hr, the resistivities increased to the range 0.3 to 300,000 ohm-cm. To correlate resistivity with crystal structure, the cadmium sulfide films were studied by means of X-ray and electron diffraction, and spectrophotometry. It was found that these cadmium sulfide films were hexagonal and highly oriented with the c-axis perpendicular to the plane of the substrate. Grain size perpendicular to the c-axis was much less than 100 A after deposition onto room-temperature substrates, and increased to 100 to 200 A in diameter after heat treatment. To determine the type of contact the commonly deposited metals make to cadmium sulfide, a mask changer was employed to allow the deposition of layerized arrays of metal-cadmium sulfide-metal in a single pumpdown. Aluminum, indium, silver, and gold were thereby deposited in several different electrode combinations. Combinations having aluminum as one (or both) of the electrodes exhibited rectifying characteristics; all other combinations exhibited ohmic characteristics. (Author).
Publisher:
ISBN:
Category : Metallic films
Languages : en
Pages : 43
Book Description
Cadmium sulfides was vacuum-deposited onto glass substrates at approximately 0.00002 torr using electron beam heating. Initial resistivities were in the range 0.1 to 1 ohm-cm. After heating in vacuum at 360 to 370C for 1/2 hr, the resistivities increased to the range 0.3 to 300,000 ohm-cm. To correlate resistivity with crystal structure, the cadmium sulfide films were studied by means of X-ray and electron diffraction, and spectrophotometry. It was found that these cadmium sulfide films were hexagonal and highly oriented with the c-axis perpendicular to the plane of the substrate. Grain size perpendicular to the c-axis was much less than 100 A after deposition onto room-temperature substrates, and increased to 100 to 200 A in diameter after heat treatment. To determine the type of contact the commonly deposited metals make to cadmium sulfide, a mask changer was employed to allow the deposition of layerized arrays of metal-cadmium sulfide-metal in a single pumpdown. Aluminum, indium, silver, and gold were thereby deposited in several different electrode combinations. Combinations having aluminum as one (or both) of the electrodes exhibited rectifying characteristics; all other combinations exhibited ohmic characteristics. (Author).
Solar Energy Update
Author:
Publisher:
ISBN:
Category : Solar energy
Languages : en
Pages : 680
Book Description
Publisher:
ISBN:
Category : Solar energy
Languages : en
Pages : 680
Book Description
Photoluminescent Properties of Vacuum Deposited Cadmium Sulfide Films
Author: William Paul Bleha (Jr)
Publisher:
ISBN:
Category :
Languages : en
Pages : 159
Book Description
Green and blue photoluminescence has been observed below 100 degrees K in vacuum deposited, low resistivity CdS films given no post deposition treatment. The films were deposited in a heated chamber inside the bell jar on fused quartz substrates held at temperatures from 140-180 degrees C. The background pressure in the vacuum system was 0.000 001 Torr. The evaporant used was chlorine-doped CdS powder. The chlorine doping activated the luminescence and gave films that had resistivities at 300 degrees K in the range of from 1 to 100 ohm-cm parallel to the substrate. The green luminescence in the films at 77 degrees K was similar to the emission reported for donor-doped CdS. The green emission spectra observed at 10 degrees K became better resolved than at 77 degrees K, and the peak position shift with temperature was small. The blue emission peak observed in the films was at 4892 A at 77 degrees K, which is in the fundamental absorption edge. Some of the literature relating to the theory and practice of CdS vacuum deposition is reviewed. Also a summary of the properties of the green luminescence of pure and donor-doped CdS is given. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 159
Book Description
Green and blue photoluminescence has been observed below 100 degrees K in vacuum deposited, low resistivity CdS films given no post deposition treatment. The films were deposited in a heated chamber inside the bell jar on fused quartz substrates held at temperatures from 140-180 degrees C. The background pressure in the vacuum system was 0.000 001 Torr. The evaporant used was chlorine-doped CdS powder. The chlorine doping activated the luminescence and gave films that had resistivities at 300 degrees K in the range of from 1 to 100 ohm-cm parallel to the substrate. The green luminescence in the films at 77 degrees K was similar to the emission reported for donor-doped CdS. The green emission spectra observed at 10 degrees K became better resolved than at 77 degrees K, and the peak position shift with temperature was small. The blue emission peak observed in the films was at 4892 A at 77 degrees K, which is in the fundamental absorption edge. Some of the literature relating to the theory and practice of CdS vacuum deposition is reviewed. Also a summary of the properties of the green luminescence of pure and donor-doped CdS is given. (Author).