Special features of charge transport in PbGa2Se4 crystals

The current-voltage (I-V) characteristics of PbGa2Se4 single crystals grown by the Bridgman-Stockbarger method with a resistivity of 1010–1012 Ω cm were measured. The value of the majority carrier mobility μ=14 cm2 V−1 s−1, calculated by the differential method of analysis of I-V characteristics, makes it possible to evaluate a number of parameters: the carrier concentration at the cathode (nc0=2.48 cm−3), the width of the contact barrier dc=5.4×10−8 cm, the cathode transparency D c * =10−5–10−4 eV, and the quasi-Fermi level EF=0.38 eV. It is found that a high electric field provides the charge transport through PbGa2Se4 crystals in accordance with the Pool-Frenkel effect. The value of the dielectric constant calculated from the Frenkel factor is found to be equal to 8.4.