Density of states effective mass of n-type CuInSe 2 from the temperature dependence of Hall coefficient in the activation regime

Abstract

The Hall coefficient R H of n-type CuInSe 2 single crystals is measured between 10 and 300 K in pulsed magnetic field up to 35 T. The threshold field B th, above which the magnetic freezeout starts to occur, varies linearly with temperature. From the analysis of the temperature dependence of electron concentration in the activation regime above 100 K at different field values, it is established that the density of states effective mass m e ∗ = ( 0.090 ± 0.001 ) m e is independent of the magnetic field B and the activation energy E D, above around 6 T, varies as B 1/3. Similar B 1/3 dependence of the magnetoresistance in the high magnetic field regime, reported earlier in the same material, suggests that theoretical work that could explain this coincidence is needed.