Submitted on October 1, 2007
Accepted on December 3, 2007
Probing the Carrier Capture Rate of a Single Quantum Level
M. Berthe 1, R. Stiufiuc 2, B. Grandidier 1*, D. Deresmes 1, C. Delerue 1, D. Stiévenard 1
1 Institut d’Electronique, de Microélectronique et de Nanotechnologie, IEMN, (CNRS, UMR 8520), Département ISEN, 41 bd Vauban, 59046 Lille Cedex, France.
2 Institut d’Electronique, de Microélectronique et de Nanotechnologie, IEMN, (CNRS, UMR 8520), Département ISEN, 41 bd Vauban, 59046 Lille Cedex, France; Present address: University Babes-Bolyai, 400084 Cluj-Napoca, Romania.
* To whom correspondence should be addressed.
B. Grandidier , E-mail: bruno.grandidier{at}isen.fr
The performance of many semiconductor quantum-based structures are governed by the dynamics of charge carriers between a localized state and a band of electronic states. Using scanning tunnelling spectroscopy, we studied the transport of inelastic tunnelling 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 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.
