HIGH-PRESSURE DETERMINATION OF ALGAINP BAND-STRUCTURE

Low temperature photoluminescence measurements have been carried out a t hydrostatic pressures up to 80 kbar to determine the band structure of the disordered (AlxGa1-x)(0.5)In0.5P alloy system. Using a series o f specifically designed samples we have measured how the Gamma, L and X conduction band energies vary with strain and aluminium content. The direct band gap varies linearly from that of GaInP at a rate of 0.61x eV. The position of the X minimum in GaInP is found to be 280 meV abo ve the Gamma, increasing linearly with aluminium content at a rate of 0.085x eV. Measurements of unstrained and 1% compressively strained Ga InP put tower limits on the Gamma(c)-L(c) separation of 125 meV and 17 5 meV, respectively.