AMORPHOUS AVALANCHE PHOTODIODE WITH LARGE CONDUCTION-BAND EDGE DISCONTINUITY

Citation
S. Sugawa et al., AMORPHOUS AVALANCHE PHOTODIODE WITH LARGE CONDUCTION-BAND EDGE DISCONTINUITY, JPN J A P 1, 35(2B), 1996, pp. 1014-1017
Citations number
9
Categorie Soggetti
Physics, Applied
Volume
35
Issue
2B
Year of publication
1996
Pages
1014 - 1017
Database
ISI
SICI code
Abstract
An amorphous avalanche photodiode (APD) with a heterojunction of hydro genated amorphous silicon carbide (a-SiC:H) and hydrogenated amorphous silicon germanium (a-SiGe:H) was formed. The band gaps of a-SiC:H and a-SiGe:H are 3.5 eV and 1.55 eV, respectively The discontinuity of co nduction bands at the heterojunction is larger than the band gap of a- SiGe:H. In this amorphous APD, photocurrent multiplication is observed under low electric field. The quantum efficiency starts to exceed uni ty when the conduction band discontinuity becomes larger than the band gap of a lower-gap material, and it is likely to saturate at 2. The s lope of photoelectric conversion characteristics is 1.00. The multipli cation is explained by the impact ionization process at the Land edge discontinuity region.