Terahertz Emission from GaAs Films on Si(100) and Si(111) Substrates Grown by Molecular Beam Epitaxy

• DOI: 10.1007/s10762-011-9765-x
• Publication Date: 2011-01-31T09:54:48Z
• Authors: Takashi Yoshioka; Satoru Takatori; Pham Hong Minh; Marilou Cadatal-R...; Tomoharu Nakazato; Toshihiko Shimizu; Nobuhiko Sarukura; Elmer Estacio; John Vincent Misa; Rafael Jaculbia; Michael Defensor; Armando Somintac; Arnel Salvador
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

We report on the terahertz emission from femtosecond-laser-irradiated GaAs layers grown on Si(100) and Si(111) substrates. The results show that the terahertz emission from GaAs on Si is stronger than that of a semi-insulating bulk GaAs crystal. This increase is attributed to the strain field at the GaAs/Si interface. In the GaAs of the Si(100) sample, the stronger terahertz emission is observed compared with GaAs on Si(111). Moreover, the effect of changing the doping type of the Si substrate from n-type to semi-insulating was also studied and it was found that the terahertz emission intensity of GaAs on semi-insulating Si(100) is stronger than that of GaAs on n-type Si(100). Finally, strong terahertz emission from GaAs on semi-insulating Si(100) was observed not only in the reflection geometry but also in the transmission geometry. These results hold promise for new applications of terahertz optoelectronics.