Accession Number:

ADA066064

Title:

Basic Studies of High Performance Multialkali Photocathodes

Descriptive Note:

Final rept. 1 Sep 1974-31 Aug 1978

Corporate Author:

STANFORD UNIV CA DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s):

• Bates, Clayton W., Jr

Report Date:

1979-03-05

Pagination or Media Count:

127.0

Abstract:

X-ray photoemission studies XPS of Cs3Sb, Na2KSb, and Na2KSbCs alkali antimonide photocathodes prepared in ultrahigh vacuum on pyrex, suprasil quartz, and stainless steel substrates have been made. The results for these surfaces are the same. Employing the concept of the Auger Parameter we demonstrate that the most photosensitive alkali-antimonide photoemitters are ionic semiconductors with a direct correlation between degree of ionicity and photosensitivity. We further show the dependence of photoemission threshold on lattice constant and ionicity. It is concluded from these studies that the structure of the most photosensitive s-20 consists of a surface layer of K2CsSb upon a base layer of Na2KSb and not a monolayer of CS upon Na2KSb as we commonly thought.

Descriptors:

• *PHOTOELECTRIC EMISSION
• *X RAY SPECTRA
• *PHOTOCATHODES
• CRYSTAL STRUCTURE
• THRESHOLD EFFECTS
• CHARGE TRANSFER
• VALENCE
• ANTIMONIDES
• ALKALI METAL COMPOUNDS
• ION DENSITY
• CARRIER MOBILITY
• LATTICE DYNAMICS
• QUANTUM EFFICIENCY
• REFRACTIVE INDEX
• FABRICATION
• EMISSION SPECTRA

Subject Categories:

• Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE