Conductivity analysis of n-GaAs molecular beam epitaxial layers using multicarrier fitting

Abstract

We have set up a model for the energy-dependent lifetime, including the effects of the charge carrier collisions with ionized impurities, polar optical phonons, and space charge. The model is then used to compute the mobility spectrum at each temperature, which used to compute the pertinent magnetic-field-dependent Hall parameters. The computed Hall parameters compared can then be measured values to estimate the validity of the lifetime model and parameters. The method has been applied to two n-GaAs∕SI–GaAs epitaxial layers containing two types of carriers. The magnetic field dependence of the Hall voltage has been observed in the studied GaAs layers. We present the numerical solution of the neutrality equation, which contains all sources of charges present in the sample, and numerical integration of the total relaxation times ⟨τ⟩ so combined that is possible to obtain the mobility of the partial charges and their part in the whole conductivity of the layer.