Terahertz-radiation generation in low-temperature InGaAs epitaxial films on (100) and (411) InP substrates

Photoconductive antennas based on epitaxial films In0.5Ga0.5As on GaAs (1 1 1)A and (1 0 0) substrates with a metamorphic buffer

“…As it was shown in our previous work [28], the intensity of THz radiation from LT-InGaAs layers on the (4 1 1)A InP wafers exceeds that from layers formed on the (1 0 0) InP wafers by a factor of 3-5. The similar behavior of THz signal we obtain for photoconductive LT-InGaAs antennas on GaAs substrates with orientations (1 1 1)A and (1 0 0) (figure 5(b)).…”

“…The purpose of the present work is to investigate the generation of terahertz pulses by biased PCA based on In 0.5 Ga 0.5 As films grown on (1 0 0)-oriented and (1 1 1)A-oriented substrates. The interest in (n 1 1)A-oriented photoconductive films is supported by recent investigations [28,29] where it was revealed that open LT-GaAs and LT-InGaAs films grown on (n 1 1)-oriented substrates GaAs and InP under pulsed laser excitation generate essentially more intensive THzradiation as compared to (1 0 0) ones. In this work we also investigate the effect of Si-doping on carrier concentration in LT-In 0.5 Ga 0.5 As (1 1 1)A-oriented films and on the THz radiation generation efficiency of the corresponding PCA.…”

Improved InGaAs and InGaAs/InAlAs Photoconductive Antennas Based on (111)-Oriented Substrates

“…It is usually assumed that fast excitation of charge carriers in InGaAs / InAlAs heterostructures occurs in InGaAs layers, whereas the diffused charge carriers are captured in InAlAs layers [28,29]. Since it was shown that the most efficient terahertz radiation was generated in samples grown on substrates with an orientation different from the traditional (100) [20][21][22], to obtain the most efficient generation, the InGaAs / InAlAs heterostructure was grown straight on InP (111)A substrate. InAlAs layers significantly increase the resulting structure resistance.…”

“…It was shown recently [20][21][22] that LT-InGaAs and LT-GaAs structures, fabricated on (n11)A-oriented GaAs or InP substrates with or without PCA electrodes, under pulsed laser excitation, can generate THz radiation with higher power as compared to structures obtained on conventional (100) substrates. It was argued that substrate orientation can influence the concentration and the type of defects in low-temperature grown films.…”

Si‐Doping of Low‐Temperature‐Grown GaAs Heterostructures on (100) and (111)A GaAs Substrates

“…The interest in LTG-GaAs (n11)A films is supported by recent publications. [18,19] It was shown that LTG-GaAs and LTG-InGaAs films grown on (n11)A-oriented GaAs and InP substrates generate essentially more intensive terahertz radiation under pulsed laser excitation as compared to (100) ones.…”