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

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.
Authors:
; ;  [1] ;  [2]
  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)
Publication Date:
OSTI Identifier:
22283266
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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