Terahertz emission enhancement in low-temperaturegrown GaAs with an n-GaAs buffer in reflection and transmission excitation geometries

• Main Authors: Prieto, Elizabeth Ann P., Vizcara, Sheryl Ann B., Somintac, Armando S., Salvador, Arnel A., Estacio, Elmer S., Que, Christopher T., Yamamoto, Kohji, Tani, Masahiko
• Format: text
• Published: Animo Repository 2014
• Subjects: Gallium arsenide; Terahertz spectroscopy; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/3819; https://animorepository.dlsu.edu.ph/context/faculty_research/article/4821/type/native/viewcontent/JOSAB.31.000291
• Institution: De La Salle University

The growth of low-temperature-grown GaAs (LTG-GaAs) on semi-insulating GaAs substrate with a 0.2 μm n-GaAs buffer demonstrated enhanced terahertz (THz) emission in reflection and transmission excitation geometries via time-domain spectroscopy. The transient photocurrent of the sample in reflection and transmission geometries resulting from ultrafast excitation yielded a 215% and 165% increase in the THz emission, respectively, as compared with a sample grown with an undoped GaAs buffer. The LTG-GaAs film with n-GaAs buffer exhibited a significant increase in its built-in field as supported by calculations and photoreflectance experiments. The enhanced THz emission intensity was comparable with bulk p-InAs. © 2014 Optical Society of America.