PHOTOLUMINESCENCE INTENSITY STUDY OF N-INP MIS STRUCTURES REALIZED WITH A NATIVE OXIDE INSULATOR FILM

The bias dependence is studied of the photoluminescence (PL) intensity of metal-insulator-n-InP structures obtained by growing native oxide by a plasma bilayer technique. The MIS structures exhibit an interface density of states dominated by a discrete level at about 0.45 eV below the conduction band. The PL intensity is thus calculated by using the Stevenson-Keyes expression for the surface recombination velocity S. By comparison of the experimental results and the calculated curves, it is concluded that S is small, in any case lower than about 10(4) cm/s. The PL changes, as a function of the bias voltage, can be understood essentially in terms of the variations of the width of the space charge layer.