Probing carrier behavior in organic semiconductor device by electric field induced optical second harmonic generation measurement

Electric field induced optical second harmonic generation (EFISHG) measurement is capable of probing carrier motions in organic devices. By measuring nonlinear polarization induced in active layer of organic devices, the carrier motion is visualized. After summarizing the conventional SHG measurement as a tool for material characterization, we show that the EFISHG is a way for probing carrier motions, and thus extends the potentiality of the conventional SHG measurement. We employ the EFISHG measurement to probe carrier behaviors in double-layer metal-insulator–metal diodes, e.g., Au/TIPS-pentacene/PI/ITO diodes, and demonstrate how the time-resolved SHG measurement probes carrier motion in the diodes, in terms of the I–V and C–V characteristics. Results give an insightful picture on the carrier injection, and the succeeding carrier transport.

Carrier injection process in Au/TIPS-pentacene/PI/ITO diode.Figure optionsDownload as PowerPoint slideHighlights
► EFISHG is capable of probing carrier motion.
► EFISHG visualizes transient carrier behaviors in Au/TIPS-pentacene/PI/ITO diodes.
► Carrier motion in diodes is visualized in terms of the I–V and C–V characteristics.