GaAsP Hall mobility characterization for GaAsP/SiGe tandem solar cell on Si substrate

This work discusses Hall effect measurements by the van der Pauw (vdP) method of thin gallium arsenide phosphide (GaAs_.84P_.16) grown on silicon (Si) substrates with graded silicon germanium (Si_yGe_1-y) working as a buffer layer. The material characterized is used as the top cell of a recently demonstrated III-V/SiGe on Si tandem cell. We report for the first time data of the Hall mobility of the material obtained through measurement of samples with different doping levels and thicknesses and at various temperatures. This data is then used for predicting device performance using a 1-D diode model. The technique can be applied as a material screening test to ensure optimal device performance.