Dependence of Hooge constant on mean free paths of materials

The Hooge parameters of compound semiconductors are found to be in inverse proportional to the mean free paths of materials. The newly developed model of 1/f phonon energy partition fluctuation in thermal equilibrium predicts the value of Hooge parameter as αH = a/λ, the ratio of the lattice constant a and the mean free path λ. Several reported experimental results on αH for very pure semiconductors are found on the a/λ line. Experimental verification is given by measuring noise in InGaAs/InAlAs heterostructure, where optical phonon effects can be observed due to negligible impurity scattering. The Hooge parameter of about 1 in p-InGaAs and 10-3 to 10-5 in n-InGaAs reflects the two order difference in the mobility and corresponding λ values.