“…where U (x, y, z) is the surface potential at a particular point (x, y, z), N a (x, y, z) is the uniform channel doping concentration, q is the electronic charge, ε s is the permittivity of silicon, p (x, y, z) is the hole concentration, ∆n is the excess carriers generated per unit volume, ∆Q is the attenuated intensity, n (x, y, z) is the electron concentration [14]. The boundary conditions used for solving Equation (1) is shown in [16].…”