Accession Number:

AD0909970

Title:

Broadband Near Infrared Laser Detector.

Descriptive Note:

Quarterly rept. no. 4, Oct-Dec 72,

Corporate Author:

VARIAN ASSOCIATES INC PALO ALTO CA

Personal Author(s):

Report Date:

1973-01-01

Pagination or Media Count:

45.0

Abstract:

Proper theoretical treatment of the transmission mode photocathode is shown to require a correct treatment both of the interfacial recombination velocity and of electron-hole pair generation in the grading region. The rate of change of lattice constant with respect to bandgap is shown to be the determining factor in obtaining a low interfacial recombination velocity. These calculations show from first principles that no better performance can ever be obtained from GaAsGaAsPGaP photocathodes than that which has been obtained experimentally already. Cooled operation of zinc-doped InGaAsP quaternary III-V photocathodes shows superior properties to either InGaAsP room temperature operation or InAsP ternary photocathodes low temperature operation. The barrier height at the InGaAsP-Cs2O interface is lowered by cooling, giving increased electron escape probability and new highs in quantum efficiency over a wide wavelength range. A 1.06-micron quantum efficiency of 7.5 per incident photon was observed at -90 C. Author

Subject Categories:

  • Electrical and Electronic Equipment
  • Lasers and Masers
  • Infrared Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE