Probing the Carrier Capture Rate of a Single Quantum Level
M. Berthe,
R. Stiufiuc,*
B. Grandidier,
D. Deresmes,
C. Delerue,
D. Stiévenard
The performance of many semiconductor quantum-based structures
is governed by the dynamics of charge carriers between a localized
state and a band of electronic states. Using scanning tunneling
spectroscopy, we studied the transport of inelastic tunneling
electrons through a prototypical localized state: an isolated
dangling-bond state on a Si(111) surface. From the saturation
of the current at an energy resonant with this state, the hole
capture rate by the dangling bond was determined. By further
mapping the spatial extension of its wave function, the localized
nature of the level was found to be consistent with the small
magnitude of its cross section. This approach illustrates how
the microscopic environment of a single defect critically affects
its carrier dynamics.
* Present address: University Babe
-Bolyai, 400084 Cluj-Napoca, Romania.
To whom correspondence should be addressed. E-mail: bruno.grandidier{at}isen.fr
