Special Features of Charge Transport in PbGa_2Se_4 Crystals

摘要

The current-voltage (I-V) characteristics of PbGa_2Se_4 single crystals grown by the Bridgman-Stockbarger method with a resistivity of 10~(10)-10~(12) Ω cm were measured. The value of the majority carrier mobility μ = 14 cm~2V~(-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 (n_(c0) = 2.48 cm~(-3)), the width of the contact barrier d_c = 5.4 * 10~(-8) cm, the cathode transparency D_c~* = 10~(-5) - 10~(-4) eV, and the quasi-Fermi level E_F = 0.38 eV. It is found that a high electric field provides the charge transport through PbGa_2Se_4 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.