Terahertz emission from gradient InGaAs surfaces

Abstract

We present an experimental study of the terahertz emission from InxGa1−xAs epitaxial layers that were grown while varying the alloy fraction x. We observe the terahertz emission that is significantly different depending on the variation direction of the alloy fraction. We attribute the difference to the significant change of the band bending induced in the growth direction and to the position-dependent variation of the effective mass.

Electric field dependence of terahertz wave emission in temperature-controlled GaAs epitaxial films

“…[3][4][5] Therefore, the terahertz emission from the transient phenomena depends on the profile of the internal electric field. [6][7][8][9][10][11][12][13] The characteristics mean that the terahertz emission can be controlled by the electric field, which is significant for the development of applications such as a terahertz emitter. In general, in order to widely control the electric field strength in the semiconductor, an external bias is applied to a complicated semiconductor structure.…”

“…19) The electric field strengths in the d = 200 (500) nm sample estimated from the linear fitted results in Fig. 1(b) are 26 (11), 29 (12), and 32 (13) kV/ cm at 263, 293, and 323 K, respectively. Therefore, the formation of instantaneous polarizations is enhanced as the temperature increases.…”