SURFACE ACOUSTIC WAVE STUDIES OF DEFECTS IN ELECTRON IRRADIATED GaAs
نویسندگان
چکیده
Surface Acoustic Waves (SAW) provide a means of studying low temperature anelastic relaxations of crystal defects produced by irradiation. Due to their confinement near the surface where radiation induced defect concentrations are highest. SAW are more sensitive than bulk ultrasonic waves in these investigations. Furthermore. for piezoelectric materials. the use of photolithographically deposited interdigital SAW transducers eliminates the ubiquitous ultrasonic bond problem faced in bulk wave experiments, facilitating annealing studies. Results are reported for 2.5 MeV electron irradiated GaAs. Two peaks in attenuation versus temperature were observed both with SAW and with bulk waves.
منابع مشابه
Surface acoustic wave propagation and inhomogeneities in low-density two-dimensional electron systems near the metal–insulator transition
We have measured the surface acoustic wave velocity shift in a GaAs/AlGaAs heterostructure containing a two-dimensional electron system (2DES) in a low-density regime (!10 cm) at zero magnetic field. The interaction of the surface acoustic wave with the 2DES is not well described by a simple model using low-frequency conductivity measurements. We speculate that this conflict is a result of inho...
متن کاملTransport and lifetime enhancement of photoexcited spins in GaAs by surface acoustic waves.
We demonstrate spin transport and spin lifetime enhancement in GaAs quantum wells induced by the traveling piezoelectric field of a surface acoustic wave (SAW). Spin transport lengths of about 3 microm corresponding to spin relaxation times during transport over 1 ns are observed, which are considerably longer than the exciton spin diffusion lengths in the absence of a SAW. The slow spin relaxa...
متن کاملSurface acoustic-wave attenuation by a two-dimensional electron gas in a strong magnetic field.
The propagation of a surface acoustic wave (SAW) on GaAs/AlGaAs heterostructures is studied in the case where the two-dimensional electron gas (2DEG) is subject to a high magnetic field and a smooth random potential with correlation length Λ and amplitude ∆. The electron wave functions are described in a quasiclassical picture using results of percolation theory for two-dimensional systems. We ...
متن کاملDefect pairs and clusters related to the EL2 centre in GaAs
2014 In this article, we attempt to consistently interpret Deep Level Transient Spectroscopy (DLTS), Electron Paramagnetic Resonance (EPR) and electrical conductivity experimental data for irradiated GaAs. Our analysis reveals the occurrence of an irradiation-induced single donor mid-gap level (MG) related to the AsGa antisite defect. We give evidence that MG can be identified with the deep lev...
متن کاملTiO2 based surface acoustic wave gas sensor with modified electrode dimensions for enhanced H2 sensing application
The design and optimization of nanostructure-based surface acoustic wave (SAW) gas sensor is analyzed based on TiO2 sensing layer and modified electrode dimensions. The sensitivity of the gas sensor depends upon the type of sensing layer used and active surface area obtained by varying the aspect ratio. The performance of the sensor is observed from 0.1ppm to 100ppm concentration of ...
متن کامل