Electrical properties of CuGaS2 single crystals

Publisher Website
Google Scholar
Abstract
The resistivity and Hall coefficient for undoped p‐type CuGaS2 were measured at temperatures between 77 and 400°K. The crystals were grown from both the stoichiometric melt and the vapor phase. The crystals were heat treated under an excess sulfur atmosphere in the temperature range 400–660°C. An analysis of the hole concentration data showed that the heat treatment changed the acceptor concentration from 6×1014 to 2×1018 cm−3. The acceptor ionization energy increased from 0.073 to 0.39 eV with the decrease of the acceptor concentration. The effective mass of the hole in CuGaS2 from the Hall analysis was ∼0.69me. The formation energy of the Cu vacancy, which is presumably an intrinsic acceptor, was ∼0.68 eV in CuGaS2. The acceptor energy of the Cu vacancy in the lower concentration limit was ∼0.12 eV. The mobility shows the dominance of lattice scattering through a deformation potential at higher temperatures than 110°K, while the observed mobility data at lower temperatures can be reasonably explained by taking into account the effect of space‐charge scattering.