Probing carrier injection into pentacene field effect transistor by time-resolved microscopic optical second harmonic generation measurement
Abstract
By probing optical second harmonic generation (SHG) signals enhanced around the injection electrode, the carrier injection mechanism of top-contact pentacene field-effect transistors (FETs) was investigated in terms of Schottky injection. At the Au source electrode, the SHG signal disappeared immediately after applying the driving voltage: the applied external electric field was cancelled by the space charge field formed by holes accumulated in the FET channel. At the Ag source electrode, the SH intensity decayed slowly. Its dependence on the device operation voltage suggested that the electric field was not relaxed by injected holes. The Schottky effect regulated carrier injection. The space charge field effect attributable to accumulated holes contributed to the carrier injection.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- July 2009
- DOI:
- Bibcode:
- 2009JAP...106a4511N
- Keywords:
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- 85.30.Tv;
- 42.65.Ky;
- 78.47.jc;
- 73.30.+y;
- Field effect devices;
- Frequency conversion;
- harmonic generation including higher-order harmonic generation;
- Time resolved spectroscopy;
- Surface double layers Schottky barriers and work functions