Indication of mixed conductivity in III-V semiconductors using conductivity, Hall effect and magnetoresistance measurements

Conductivity, Hall effect and magnetoresistance quantities in III-V semicon ductors are analyzed with regard to both electron and hole transport parame ters. A systematic equation set valid for the mixed conductivity regime is reviewed. It is shown that a high ratio of the geometric-magnetoresistance mobility to the Hall mobility (larger than about 1.2) together with a suffi ciently low conductivity (close to the intrinsic one) are the most importan t factors indicating the presence of a mixed conductivity. For demonstratio n, examples with semi-insulating GaAs and InP are shown at room temperature .