Accession Number:

AD0006049

Title:

PHOTOCURRENT, SPACE-CHARGE BUILD-UP AND FIELD EMISSION IN ALKALI HALIDE CRYSTALS

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR INSULATION RESEARCH

Personal Author(s):

• von Hippel, A.
• Gross, E. P.
• Jelatis, J. G.
• Geller, M.

Report Date:

1953-02-01

Pagination or Media Count:

42.0

Abstract:

Research is discussed on the formation of space charges, the re lease of electrons from the cathode, and their transconductance through a dielectric. The considerations are based on additively colored alkali halide crystals which represent a transparent solid with frozen-in-electrons that can be mobilized by light absorption. When these electrons move toward the anode, they leave a positive space charge an adjustable cathode fall results which can be steepened until electrons are released by field emission. The steady-state and transient solutions for the charging and discharging cycle were calculated. The effects of light intensity, wave length, and field emission are discussed. KBr crystals were investigated experimentally as a function of time, voltage, light intensity, and color-center density. Field emission was produced with voltages as low as 1 v, and a field-emission photocell was realized.

Descriptors:

• *FIELD EMISSION
• *SALTS
• DENSITY
• INTENSITY
• LIGHT
• TRANSPARENCE
• CRYSTALS
• ELECTRONS
• CATHODES
• HALIDES
• ABSORPTION
• SPACE CHARGE
• TRANSCONDUCTANCE
• ELECTRIC CHARGE
• COLOR CENTERS
• ALKALI METAL COMPOUNDS
• PHOTOELECTRIC CELLS(SEMICONDUCTOR)
• FREQUENCY
• TRANSIENTS

Subject Categories:

• Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE