Raman, Photoconductive, and Acoustoelectric Probes of Residual Deep Impurities and Absorption in GaAs
We present several techniques to test and characterize GaAs for residual deep impurities and weak optical absorption at 1.06 µ. 90° Raman scattering intensities were measured as a function of position along a sample to probe the attenuation of a collimated YAG laser beam and to obtain the absorption coefficient. The absorption at 1.06 µ may be due to native defects. Their concentration was obtained from saturation photoconductive studies with intense Q-switched YAG laser radiation. A 25 fold increaselin conductivity yielded a defect concentration of ≈ 1016 cm−3. In addition we have used propagating acoustoelectric domains, ≈ 1 mm wide, to scan the sample for inhomogeneities in both dark and photoexcited carrier concentration.
KeywordsHigh Light Intensity Raman Line Free Electron Concentration Electron Capture Cross Section Raman Scattered Light
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