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High current density GaN∕CsBr heterojunction photocathode with improved photoyield

Authors :
Zhi Liu
Juan R. Maldonado
Yun Sun
Roger Fabian W. Pease
Scott Schuetter
Piero Pianetta
Source :
Applied Physics Letters. 90:231115
Publication Year :
2007
Publisher :
AIP Publishing, 2007.

Abstract

A four fold improvement in photoyield has been observed in GaN films coated with CsBr films (CsBr∕GaN) relative to CsBr∕Cr photocathodes reported in previous studies. A model is presented involving photoemission from intraband states in the CsBr film and direct electron injection through the CsBr film from the GaN substrate. The lifetime of the films at high current density >90A∕cm2 is limited by the temperature rise in the GaN films caused by the high photon absorption at 257nm. The lifetime can be improved by utilizing a cooled substrate or a high thermal conductivity substrate under the GaN films.

Details

ISSN :
10773118 and 00036951
Volume :
90
Database :
OpenAIRE
Journal :
Applied Physics Letters
Accession number :
edsair.doi...........f4b767434f7ad3704975a568999b22e7
Full Text :
https://doi.org/10.1063/1.2746959