Measurement and analysis of electronic properties of Hg_(1-x)Mn_xTe wafers

Electronic properties of several Hg_1-xMn_xTe wafers are characterized by Van Der Pauw method at 77K and room temperature respectively.It is found that the conductivity type of a part of Hg_1xMn_xTe wafers change from p type at 77K 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-xMn_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.