6.4 The energy band diagram pictured in Fig. P6.4 characterizes a Si sample maintained at room temperature. Note that E EEG/4 at x = ±L and E; Er Ec/4 at x = 0. = -L 0 L Figure P6.4 Ec EF E₁ Ex (a) The semiconductor is in equilibrium. How does one deduce this fact from the given en- ergy band diagram? (b) What is the electron current density (JN) and hole current density (JP) at x = +L/2? (c) Roughly sketch n and p versus x inside the sample. (d) Is there an electron diffusion current at x =+L/2? If there is a diffusion current at a given point, indicate the direction of current flow. (e) Sketch the electric field (8) inside the semiconductor as a function of x. (f) Is there an electron drift current at x = ±L/2? If there is a drift current at a given point, indicate the direction of current flow.