Čerenkovův limit pro Si, GaAs and GaP ve ztrátové spektroskopii energie elektronů

The Čerenkov limit of Si, GaAs and GaP in electron energy loss spectrometry

journal article in Web of Science

en

Since the advent of monochromated electron energy loss spectrometry (EELS) the experimental detection of band gaps in semiconducting materials is of great importance. In the non-relativistic limit of this technique the onset of the inelastic signal represents the band gap. But due to relativistic energy losses, like Čerenkov losses and the corresponding light guiding modes, appearing at high beam energies the band gap is usually hidden. The highest beam energy, which does not excite relativistic losses in a certain material, is called the Čerenkov limit of the material. In this work the low loss EELS signals of Si, GaAs and GaP are measured at various beam energies and the calculated Čerenkov limits are experimentally confirmed.

V publikaci se zabýváme teoretickým a experimentálním stanovením Čerenkovova limitu pro Si, GaAs and GaP ve ztrátové spektroskopii energie elektronů

Since the advent of monochromated electron energy loss spectrometry (EELS) the experimental detection of band gaps in semiconducting materials is of great importance. In the non-relativistic limit of this technique the onset of the inelastic signal represents the band gap. But due to relativistic energy losses, like Čerenkov losses and the corresponding light guiding modes, appearing at high beam energies the band gap is usually hidden. The highest beam energy, which does not excite relativistic losses in a certain material, is called the Čerenkov limit of the material. In this work the low loss EELS signals of Si, GaAs and GaP are measured at various beam energies and the calculated Čerenkov limits are experimentally confirmed.

Nízkoenergiový EELS, Zakázaný pás; Čerenkovovo záření

Low voltage EELS; Band gap; Čerenkov radiation

2015

06.06.2015

0304-3991

157

1

73–78

6