Analysis of impurity distribution in n-GaAs layers by photoconductivity and cyclotron resonance measurements

High-purity GaAs layers of 8 to 80 μm thickness on semi-insulating substrates have been investigated. From the 1s-2p transition of shallow donors the dopants are identified and the exact transition energies determined.

Using the relation Δω √N_I from cyclotron emission measurements the total ionized impurity density N_I was determined. In homogeneous samples a good agreement between the impurity density determined from the cyclotron resonance linewidth with total impurity density values obtained from Hall mobility data is found.

The photoconductivity and transmission measurements show the same linewidth on impurity dependence for the different types of shallow donors.