DIRECT MEASUREMENT OF BAND OFFSETS IN GAINP ALGAINP USING HIGH-PRESSURE/

High pressure photoluminescence experiments carried out at 2 K in the diamond anvil cell have been used to determine band offsets in GaInP/A lGaInP as functions of aluminium content and strain. We have used accu rate measurements of the positions of the conduction band Gamma and X minima to design samples specifically for high pressure experiments in which we have measured the band offsets. In the case of unstrained Ga InP/(Al(x)Ga1-x)(0.5)In0.5P we obtain a value for the conduction band offset (Delta E(c)) of Delta E(c) = 0.73 Delta E(g) independent of x. We have also measured samples in which the effects of aluminium conten t and strain are combined (typical of many laser devices). A 1% compre ssively strained quantum well in (Al0.3Ga0.7)(0.5)In0.5P barriers give s Delta E(c) = 0.7 +/- 0.07 Delta E(g).