PHOTOACOUSTIC MEASUREMENTS OF THE THERMAL-PROPERTIES OF ALYGA1-YAS ALLOYS IN THE REGION -LESS-THAN-OR-EQUAL-TO-Y-LESS-THAN-OR-EQUAL-TO-0.5

In this paper we present a thermal characterization of AlyGa1-yAs allo ys grown by liquid phase epitaxy on GaAs substrates, by means of the o pen photoacoustic cell detection technique and the temperature-rise me thod under continuous Light illumination. The values of the thermal co nductivity, diffusivity and specific heat were obtained in the 0 less than or equal to y less than or equal to 0.5 region, where the Al(y)Ga (1-y)AS band gap is mainly direct. The technique presented here is bas ed upon an effective sample model which is shown to be suitable for th e determination of the thermal properties of two layer semiconductor s pecimens.