3. With the concept of diffusion, let's figure out the thermal conductivity by carriers. As discussed in the lectures, the carrier flux across a unit area per unit time is 1/4nv, where n is the carrier . . . . 2 concentration and V Is the average speed, and the carriers on average can only arrive fromgl away from the interface. But instead of a density gradient, we now have a temperature gradient across the interface (dedx). We further assume that for dilute carriers, their average kinetic . . . . 3k?" 1 ,, energy (Ie, heat) Is directly determined by the temperature: 7:5131 v2 (knowns as equipartition of energy). Show that the heat flux is proportional to the temperature gradient through a thermal conductivity coefficient AQ : 1%. What is the expression of PL in this simple example? (If the carrier flux carries some other physical quantities, one can also find their corresponding coefficients in this way. Note this is only the carrier contribution, and phonons tend to conduct much more heat in most semiconductors.)