Measurement and analysis of electronic properties of Hg_1-xMn_xTe wafers

Electronic properties of several Hg_1-xMn_xTe wafers are characterized by Van Der Pauw method at 77 K and room temperature respectively. It is found that the conductivity type of a part of Hg_1-xMn_xTe wafers change from p type at 77 K to n type at room temperature. The reasons are explained through theoretical analysis. The analysis shows that high ratio of electron to hole drift mobility and narrow forbidden band of Hg_1-x Mn_xTe play key roles. Theoretical analysis of other electronic properties of Hg_1-xMn_xTe wafers shows that Van Der Pauw method does not suit to test carrier concentration and drift mobility of Hg_1-xMn_xTe wafers at room temperature, but it can be used to test resistivity and Hall coefficient.