Conductivity, Thermoelectric Power, and Valence-Band Structure of Thallium Selenide

Electrical conductivity and thermoelectric power of lead-doped thallium selenide (TlSe) of various doping concentrations have been measured. It is found that the material always remains p type. At room temperature, thermoelectric power shows a maximum for a certain value of conductivity and thereafter decreases with increase of conductivity. A qualitative discussion of the applicability of the two-valence-band model is also presented.