ECE 440 Homework XIFall 2005Due: Wednesday, October 26, 20051.A Schottky barrier is formed between a metal having a work function of 4.2 eV and p-type Si(electron affinity = 4 eV). The acceptor doping in the Si is 5x1017/cm3. (a) Draw theequilibrium band diagram showing a numerical value for qV . (b) Draw the band diagram with0.3 V forward bias with details including the width of the depletion region and other quantities.(c) Repeat part (b) for 2V reverse bias.2. Assume that a p+-n diode with a uniform cross section area, A, is built with an n regionwidthsmaller than a hole diffusion length (< Lp). This is the so-called narrowbase diode. Since for this case holes are injected into a short n region under forwardbias, we cannot use the assumption δp(xn= ∞) = 0 in Eq. 4-35. Instead, we must useas a boundary condition the fact that
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