Abstract

Terahertz emission from a Si metal-oxide-semiconductor (MOS) structure with transparent indium tin oxide electrodes was measured using a Laser Terahertz Emission Microscope (LTEM) with time-domain spectroscopy technique. The THz waveform and amplitude at various external voltage were compared with the capacitance-voltage characteristics. The observed peak amplitude strongly correlated with the surface potential and the THz waveform inverted near the flat-band voltage. This result strongly suggest that the LTEM can quantitatively measure the surface band bending of Si and can be applied as an evaluation technique of the Si MOS devices and the passivated surfaces of Si solar cells.

© 2016 Optical Society of America