Accession Number : AD0006049


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


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


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/006049.pdf


Report Date : Feb 1953


Pagination or Media Count : 42


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