Ultrasonic spectroscopy in p-type silicon

Abstract

From ultrasonic resonant absorption over a wide frequency range we have determined the distribution of the energy splittings of the acceptor ground state in very pure Si(B) crystals. The measured distributions with maxima of the order of 10μeV fit well to the expected electric field distribution from the~ 10 12 cm-3 residual donors. The critical intensity for saturating the resonance attenuation has been measured in crystals of various acceptor concentrations and as a function of temperature. Although the average distance of acceptor atoms is much greater than the Bohr-radius of the bound defect-electrons, relaxation times are found to be shortened by the acceptor-acceptor interaction.