Photoacoustic measurements of the thermal properties of AlyGa1-yAs alloys in the region 0<=y<=0.5

In this paper we present a thermal characterization of AlyGa1-yAs alloys grown by liquid phase epitaxy on GaAs substrates, by means of the open photoacoustic cell detection technique and the temperature-rise method under continuous Light illumination. The values of the thermal conductivity, 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 based upon an effective sample model which is shown to be suitable for the determination of the thermal properties of two layer semiconductor specimens.