Ultra-broadband terahertz time-domain ellipsometric spectroscopy utilizing GaP and GaSe emitters and an epitaxial layer transferred photoconductive detector

Journal Article · Mon Feb 03 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4862974· OSTI ID:22283266

Yamashita, Masatsugu; Takahashi, Hideki; Otani, Chiko ^[1]; Ouchi, Toshihiko ^[2]

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1. RIKEN Center for Advanced Photonics, 519-1399 Aobaaramaki, Aoba-ku, Sendai 980-0845 (Japan)
2. Corporate R and D Headquarters, Canon Inc., 30-2 Shimomaruko 3-Chome, Ohta-ku, Tokyo 145-8501 (Japan)

We present a reflection-type ultra-broadband terahertz (THz) time-domain spectroscopic ellipsometry system covering the frequency range of 0.5–30 THz. GaP (110) and z-cut GaSe crystals are used as emitters to generate the THz and mid-infrared pulses, respectively, and a photoconductive antenna switch using a low-temperature grown GaAs epitaxial layer transferred on Si substrate was used as a detector. By changing the emitter between the GaP and GaSe crystals, the measurable frequency range can be easily switched from the 0.5–7.8 THz range to the 7.8–30 THz range without additional optical alignment. We demonstrated the measurement of the dielectric function in a p-type InAs wafer and the optical conductivity of an indium tin oxide (ITO) thin film. The obtained carrier density and the mobility of the ITO thin film show good agreement with that obtained by the Hall measurement.

• OSTI ID: 22283266
• Journal Information: Applied Physics Letters, Vol. 104, Issue 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARRIER DENSITY
CARRIER MOBILITY
CRYSTALS
ELLIPSOMETRY
EPITAXY
FREQUENCY DEPENDENCE
GALLIUM ARSENIDES
GALLIUM PHOSPHIDES
GALLIUM SELENIDES
INDIUM ARSENIDES
LAYERS
PHOTOCONDUCTIVITY
P-TYPE CONDUCTORS
SPECTROSCOPY
SUBSTRATES
TEMPERATURE DEPENDENCE
THIN FILMS
THZ RANGE
TIN OXIDES