Composition dependence of Au/InxAl1−xAs Schottky barrier heights

The surface barrier heights φbn and room-temperature band gaps Eg of Si-doped InxAl1−xAs layers grown by molecular beam epitaxy on n-type (100) oriented InP substrates have been determined as a function of composition with capacitance versus voltage, internal photoemission, photoluminescence, and double-crystal x-ray rocking curve measurements for 0.45<x<0.55. The results indicate that Eg and φbn are linear functions of x; they also suggest that φbn (0.78)=0 and, for x>0.78, n-type surfaces might be accumulated and p-type surfaces are likely to be inverted.