Investigation of electronic conductivity in PbI2:Hf single crystals

<p>A study of the electron-hole conductivity in PbI₂ single crystals doped with Hf (0.2 wt %) was conducted using the Wagner polarization cell method. The influence of the Hf alloying admixture (0.2 mass%) on the nature and parameters of lead diiodide’s electronic conductivity has been analyzed.</p><p>Basing on the received current-potential dependences, p-type conductivity of a single crystal PbI₂:Hf was established. The hole conductivity values (s_р^о) were determined in the studied temperature range allowing to construct temperature dependence. The s_р^о value for single crystal PbI₂:Hf increased responsively to increasing temperature. For PbI₂ and PbI₂:Hf, a comparative analysis of the electron-hole conductivity was carried out. This investigation allowed determining the activation energy s_р^о reduction from 0.47 eV to 0.32 eV due to hafnium doping. Consequently, the presence of Hf admixture in PbI₂ crystals causes new impurity acceptor levels located at a distance of 0.64 eV from the upper limit of the valence zone.</p> <p> </p>