PRESSURE AND ALLOY-COMPOSITION DEPENDENCE OF AL GA1-XALXAS(100) SCHOTTKY BARRIERS/

The dependence on hydrostatic pressure and alloy composition of the Sc hottky-barrier height at ideal, defect-free, Al/Ga1-xAlxAs (100) junct ions is investigated by means of an ab initio pseudopotential approach . The results reproduce closely the experimental data and, in contrast to recent proposals, demonstrate that the barrier heights can be expl ained without invoking interface defects. The alloy-composition depend ence is understood by extending to metal/semiconductor contacts the li near-response-theory approach currently used for semiconductor heteroj unctions. The pressure variation of the barriers can be obtained from the Ga1-xAlxAs band-edge deformation potentials.