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Pure GaAs and GaAs 1−x Bi x alloys with different Bi ratios (1 %, 2.5 %, 3.5 %) fitted with silver contacts were measured with a dielectric spectroscopy device. Dielectric characterization was performed at room temperature in the frequency range of 0.1 Hz to 1 MHz. GaAs exhibits three relaxation regions corresponding to space-charge, dipolar and ionic polarizations in sequence with increasing frequency while GaAs 1−x Bi x samples show only a broad dipolar polarization in the same frequency range. This result proves the filling of the lattice with Bi through making a new bonding reducing the influence of ionic polarization. This finding supports the previous results concerning optical properties of GaAs 1−x Bi x , presented in the literature.

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Thalium selenide (TlSe), which has a lattice with tetragonal symmetry, is a member of the A3B6 semiconductor group. The structure of TlSe is defined as chains where atoms inside are bonded with an ionic-covalent bond. TlSe thin films were deposited by thermal evaporation under a high vacuum on glass substrates. The structure of TlSe thin films is amorphous with a tetragonal structure. The AC conductivity measurements were operated via the measurements of capacitance and dielectric dissipation (tanδ) at room temperature. AC conductivity values change between 10−11 and 10−6 S/cm at the low-frequency side with decreasing thickness. Two different conduction regions were observed with increasing frequency. The region observed at the low-frequency side can be attributed to the motion of a chain-like part of the lattice, while the region observed at the high-frequency side can be attributed to side groups.