Consider an n-type semiconductor with N_D = 10^{15} cm^{-3}NDâ=1015cmâ3. There is a uniform applied electric field, E = 10^5 \: V/cmE=105V/cm, throughout the semiconductor. At t = 0t=0, the semiconductor was illuminated by a sharply focused pulse of laser to create an excess hole concentration of \Delta p(t=0) = 10^{12} cm^{-3}Îp(t=0)=1012cmâ3 at x = 0x=0.Find the expression for the excess hole concentration, \Delta p(x, t)Îp(x, t), as a function of xx and tt for t > 0t>0, i. e. after the laser pulse is gone. Write your expression in terms of applied electric field, EE, generation rate GG, minority carrier lifetime, \tauÏ, diffusion coefficient, DD and mobility, \muμ. Subscript p can be omitted for simplicity.