Electron Barriers in Al-Al2O3-SnTe and Al-Al2O3-GeTe Tunnel Junctions

The tunneling characteristics of junctions consisting of two normal metals separated by a thin insulating film have been analyzed theoretically,
¹
,
²
and the main features of the analyses have been corroborated by extensive experimental studies. On the other hand, relatively little attention has been given to junctions in which one of the metals is replaced by a semiconductor.
³
Recently, we showed that, under certain conditions, such junctions exhibit a negative resistance, as in the Al-Al
2
O
3
-SnTe system.
^4,5
We have continued that investigation and now have derived the electron barrier heights of that system, and have extended our studies to the system in which GeTe replaces SnTe.