Trapping Recombination Process and Persistent Photoconductivity in Semi-Insulating 4H SiC
The decay kinetics of a persistent photoconductivity (PPC) in undoped semi-insulating 4H SiC and intercenter charge transfer were studied with EPR, photo-EPR and optical admittance spectroscopy (OAS). A thermally activated charge transfer process that occurs in the dark has been observed. The PPC ef...
Gespeichert in:
Veröffentlicht in: | Materials science forum 2006-10, Vol.527-529, p.563-566 |
---|---|
Hauptverfasser: | , , , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | The decay kinetics of a persistent photoconductivity (PPC) in undoped semi-insulating
4H SiC and intercenter charge transfer were studied with EPR, photo-EPR and optical admittance
spectroscopy (OAS). A thermally activated charge transfer process that occurs in the dark has been
observed. The PPC effect was observed directly in changes in the quality factor of the EPR cavity
before and after illumination and by the decay of the OAS signal for deep levels, and indirectly by
the excitation and decay of the nitrogen and boron EPR lines that were not observed in the dark
before illumination. The decay kinetics of the PPC and photo-induced carrier capture by nitrogen
and boron levels were found to follow a stretched exponential form. The PPC in the temperature
range from 77 to 300K was found to be produced by a thermally induced charge transfer process
involving deep trap levels. |
---|---|
ISSN: | 0255-5476 1662-9752 1662-9752 |
DOI: | 10.4028/www.scientific.net/MSF.527-529.563 |