Hg_(1-x)Mn_xTe晶片电学参数的测量及分析

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

采用范德堡法分别在77K和室温下对多个Hg1-xMnxTe晶片的电学性能进行了测量,发现部分晶片在77K下的导电类型为p型,而在室温下却为n型。通过理论分析对此现象进行了解释。分析表明:Hg1-xMnxTe晶片中电子迁移率与空穴迁移率的比值较大和Hg1-xMnxTe的禁带较窄是造成晶片导电类型转变的主要原因。对所测其它电学参数的理论分析表明范德堡法不适合用于Hg1-xMnxTe晶片室温时的载流子浓度和迁移率的测量,但仍可用其对晶片室温时的电阻率和霍尔系数进行测量。

Electronic properties of several Hg1-x Mnx Te 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 Hg1-x MnxTe 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 Hg1-x MnxTe play key roles. Theoretical analysis of other electronic properties of Hg1-x MnxTe wafers shows that Van Der Pauw method does not suit to test carrier concentration and drift mobility of Hg1-xMnxTe wafers at room temperature, but it can be used to test resistivity and Hall coefficient.