Deep levels in Ga1−xAlxAs under pressure

Publisher Website
Google Scholar
Abstract
Hall electron concentration as a function of temperature (80≲T⩽300 K) has been measured on samples of Ga1−xAlxAs with compositions x in the range 0.23⩽x⩽0.32. The measurements are repeated for the same crystals and for various constant hydrostatic pressures to alter their band structure. The results show that a deep level is present in the crystals whose activation energy initially increases with pressure, being 5 and 145 meV for P=0 and 20 kbars, respectively, for x=0.23. For P≳20 kbars, the activation energy decreases monotonically with pressure, reaching a value of 90 meV at 50 kbars. The results show that the deep level is principally associated with the indirect conduction band minima L and X in Ga1−xAlxAs.